Class UniversalActionResponse

// A universal action that opens a link.
const openLinkUniversalAction = CardService.newUniversalActionResponseBuilder()
    .setOpenLink(CardService.newOpenLink()
        .setUrl("https://www.google.com"))
        .build();

const cardBuilder1 = CardService.newCardBuilder();
const cardBuilder2 = CardService.newCardBuilder();
// Finish building the cards ...

// A universal action that shows two static cards.
const cardsUniversalAction = CardService.newUniversalActionResponseBuilder()
    .displayAddOnCards([
        cardBuilder1.build(),
        cardBuilder2.build(),
    ]).build();