• A CarouselCard is a card that can be displayed as a carousel item.

• CarouselCard is available for Google Workspace add-ons and Google Chat apps.

• You can add widgets to the footer or the main body of the CarouselCard using the addFooterWidget and addWidget methods respectively.

• Both addFooterWidget and addWidget methods return the CarouselCard object for chaining.

const carouselCard = CardService.newCarouselCard()
    .addWidget(
        CardService.newTextParagraph().setText('a text paragraph in the carousel card'))
    .addFooterWidget(
        CardService.newTextParagraph().setText('a text paragraph in the carousel card footer'));

Detailed documentation