Создайте HTTP-приложение Google Chat.

// The ID of the slash command "/about".
// It's not enabled by default, set to the actual ID to enable it. You need to
// use the same ID as set in the Google Chat API configuration.
const ABOUT_COMMAND_ID = "";

/**
 * Google Cloud Function that responds to messages sent from a
 * Google Chat space.
 *
 * @param {Object} req Request sent from Google Chat space
 * @param {Object} res Response to send back
 */
exports.avatarApp = function avatarApp(req, res) {
  if (req.method === 'GET' || !req.body.message) {
    return res.send('Hello! This function is meant to be used ' +
      'in a Google Chat Space.');
  }

  // Stores the Google Chat event as a variable.
  const event = req.body;

  // Checks for the presence of a slash command in the message.
  if (event.message.slashCommand) {
    // Executes the slash command logic based on its ID.
    // Slash command IDs are set in the Google Chat API configuration.
    switch (event.message.slashCommand.commandId) {
      case ABOUT_COMMAND_ID:
        return res.send({
          privateMessageViewer: event.user,
          text: 'The Avatar app replies to Google Chat messages.'
        });
    }
  }

  const sender = req.body.message.sender.displayName;
  const image = req.body.message.sender.avatarUrl;
  const data = createMessage(sender, image);
  res.send(data);
};

/**
 * Creates a card with two widgets.
 * 
 * @param {string} displayName the sender's display name
 * @param {string} avatarUrl the URL for the sender's avatar
 * @return {Object} a card with the user's avatar.
 */
function createMessage(displayName, avatarUrl) {
  return {
    text: 'Here\'s your avatar',
    cardsV2: [{
      cardId: 'avatarCard',
      card: {
        name: 'Avatar Card',
        header: {
          title: `Hello ${displayName}!`,
        },
        sections: [{ widgets: [{
          textParagraph: { text: 'Your avatar picture: ' }
        }, {
          image: { imageUrl: avatarUrl }
        }]}]
      }
    }]
  };
}

from typing import Any, Mapping

import flask
import functions_framework

# The ID of the slash command "/about".
# It's not enabled by default, set to the actual ID to enable it. You need to
# use the same ID as set in the Google Chat API configuration.
ABOUT_COMMAND_ID = ""

@functions_framework.http
def avatar_app(req: flask.Request) -> Mapping[str, Any]:
  """Google Cloud Function that handles requests from Google Chat

  Args:
      flask.Request: the request

  Returns:
      Mapping[str, Any]: the response
  """
  if req.method == "GET":
    return "Hello! This function must be called from Google Chat."

  request_json = req.get_json(silent=True)

  # Checks for the presence of a slash command in the message.
  if "slashCommand" in request_json["message"]:
    # Executes the slash command logic based on its ID.
    # Slash command IDs are set in the Google Chat API configuration.
    if request_json["message"]["slashCommand"]["commandId"] == ABOUT_COMMAND_ID:
      return {
        "privateMessageViewer": request_json["user"],
        "text": 'The Avatar app replies to Google Chat messages.'
      }

  display_name = request_json["message"]["sender"]["displayName"]
  avatar = request_json["message"]["sender"]["avatarUrl"]
  response = create_message(name=display_name, image_url=avatar)
  return response


def create_message(name: str, image_url: str) -> Mapping[str, Any]:
  """Google Cloud Function that handles requests from Google Chat

  Args:
      str name: the sender's display name.
      str image_url: the URL for the sender's avatar.

  Returns:
      Mapping[str, Any]: a card with the user's avatar.
  """
  return {
    "text": "Here's your avatar",
    "cardsV2": [{
      "cardId": "avatarCard",
      "card": {
          "name": "Avatar Card",
          "header": { "title": f"Hello {name}!" },
          "sections": [{
            "widgets": [{
              "textParagraph": { "text": "Your avatar picture:" }
            }, {
              "image": { "imageUrl": image_url }
            }]
          }]
      }
    }]
  }

import java.util.List;

import com.google.api.services.chat.v1.model.CardWithId;
import com.google.api.services.chat.v1.model.GoogleAppsCardV1Card;
import com.google.api.services.chat.v1.model.GoogleAppsCardV1CardHeader;
import com.google.api.services.chat.v1.model.GoogleAppsCardV1Image;
import com.google.api.services.chat.v1.model.GoogleAppsCardV1Section;
import com.google.api.services.chat.v1.model.GoogleAppsCardV1TextParagraph;
import com.google.api.services.chat.v1.model.GoogleAppsCardV1Widget;
import com.google.api.services.chat.v1.model.Message;
import com.google.cloud.functions.HttpFunction;
import com.google.cloud.functions.HttpRequest;
import com.google.cloud.functions.HttpResponse;
import com.google.gson.Gson;
import com.google.gson.JsonObject;

public class App implements HttpFunction {
  private static final Gson gson = new Gson();

  // The ID of the slash command "/about".
  // It's not enabled by default, set to the actual ID to enable it. You need to
  // use the same ID as set in the Google Chat API configuration.
  private static final String ABOUT_COMMAND_ID = "";

  @Override
  public void service(HttpRequest request, HttpResponse response) throws Exception {
    JsonObject body = gson.fromJson(request.getReader(), JsonObject.class);

    if (request.getMethod().equals("GET") || !body.has("message")) {
      response.getWriter().write("Hello! This function must be called from Google Chat.");
      return;
    }

    // Checks for the presence of a slash command in the message.
    if (body.getAsJsonObject("message").has("slashCommand")) {
      // Executes the slash command logic based on its ID.
      // Slash command IDs are set in the Google Chat API configuration.
      JsonObject slashCommand = body.getAsJsonObject("message").getAsJsonObject("slashCommand");
      switch (slashCommand.get("commandId").getAsString()) {
        case ABOUT_COMMAND_ID:
        JsonObject aboutMessage = new JsonObject();
        aboutMessage.addProperty("text", "The Avatar app replies to Google Chat messages.");
        aboutMessage.add("privateMessageViewer", body.getAsJsonObject("user"));
          response.getWriter().write(gson.toJson(aboutMessage));
          return;
      }
    }

    JsonObject sender = body.getAsJsonObject("message").getAsJsonObject("sender");
    String displayName = sender.has("displayName") ? sender.get("displayName").getAsString() : "";
    String avatarUrl = sender.has("avatarUrl") ? sender.get("avatarUrl").getAsString() : "";
    Message message = createMessage(displayName, avatarUrl);
    response.getWriter().write(gson.toJson(message));
  }

  Message createMessage(String displayName, String avatarUrl) {
    GoogleAppsCardV1CardHeader cardHeader = new GoogleAppsCardV1CardHeader();
    cardHeader.setTitle(String.format("Hello %s!", displayName));

    GoogleAppsCardV1TextParagraph textParagraph = new GoogleAppsCardV1TextParagraph();
    textParagraph.setText("Your avatar picture: ");

    GoogleAppsCardV1Widget avatarWidget = new GoogleAppsCardV1Widget();
    avatarWidget.setTextParagraph(textParagraph);

    GoogleAppsCardV1Image image = new GoogleAppsCardV1Image();
    image.setImageUrl(avatarUrl);

    GoogleAppsCardV1Widget avatarImageWidget = new GoogleAppsCardV1Widget();
    avatarImageWidget.setImage(image);

    GoogleAppsCardV1Section section = new GoogleAppsCardV1Section();
    section.setWidgets(List.of(avatarWidget, avatarImageWidget));

    GoogleAppsCardV1Card card = new GoogleAppsCardV1Card();
    card.setName("Avatar Card");
    card.setHeader(cardHeader);
    card.setSections(List.of(section));

    CardWithId cardWithId = new CardWithId();
    cardWithId.setCardId("previewLink");
    cardWithId.setCard(card);

    Message message = new Message();
    message.setText("Here's your avatar");
    message.setCardsV2(List.of(cardWithId));

    return message;
  }
}

<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>com.google.chat</groupId>
  <artifactId>avatar-app</artifactId>
  <version>1.0-SNAPSHOT</version>

  <properties>
    <maven.compiler.target>17</maven.compiler.target>
    <maven.compiler.source>17</maven.compiler.source>
  </properties>

  <dependencies>
    <dependency>
      <groupId>com.google.cloud.functions</groupId>
      <artifactId>functions-framework-api</artifactId>
      <version>1.0.1</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/com.google.code.gson/gson -->
    <dependency>
        <groupId>com.google.code.gson</groupId>
        <artifactId>gson</artifactId>
        <version>2.9.1</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/com.google.apis/google-api-services-chat -->
    <dependency>
      <groupId>com.google.apis</groupId>
      <artifactId>google-api-services-chat</artifactId>
      <version>v1-rev20230115-2.0.0</version>
    </dependency>
  </dependencies>

  <!-- Required for Java 11 functions in the inline editor -->
  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-compiler-plugin</artifactId>
        <version>3.8.1</version>
        <configuration>
          <excludes>
            <exclude>.google/</exclude>
          </excludes>
        </configuration>
      </plugin>
    </plugins>
  </build>
</project>