I post simple message with cards_v2. I placed a Button with properties:
action: {
function = "myAction",
interaction = "OPEN_DIALOG"
}
When I click on button I receive event but no DialogEventType is provided. I tried to reply with Dialog payload, but Google says bad response.
I used this: https://developers.google.com/chat/how-tos/dialogs?hl=en#apps-script
Dialog buttons works only if I send a response on message. When I posted cards through API POST it doesn't work.
I can't say is this a bug of Feature.