Webex teams channel PostBack button templates

Hi,

There is a ask from one of the customers to deploy the bot in webex teams channel, currently the bot is in web channel. I was exploring the templates for webex channel. From webex developer website I see that they are using adaptive cards v1.2 but it looks like there is no support for postback buttons, which are very important for the bot. Can any one help implement postback bottons in webex teams channel.

Thanks.