When you send an update to the message, that gets handled differently. The format of the message JSON changes to the below:
{
"type": "message",
"summary": "Set this to a summary that you want to appear in the desktop/mobile notification in Teams",
"attachments": [
{
"contentType": "application/vnd.microsoft.card.adaptive",
"contentUrl": null,
"content": {
"$schema": "http://adaptivecards.io/schemas/adaptive-card.json",
"type": "AdaptiveCard",
"version": "1.5",
"body": [
// Here you will place all of the JSON for the various pieces of your message that you want to send to Teams. I recommend using the Adaptive Card Designer and Actionable Messages Designers to figure out the formatting. When formatting the message this time, do not forget to add the JSON for your action buttons. See the "Formatting Action Buttons" page for how I handled this.
],
"padding": "None",
"msteams": {
"width": "Full"
}
}
}
],
"msteams": {
"width": "Full"
}
}
Additionally, the sub-workflow for updating the message will also need the "card_id" and "card_activity_id" that you received in the response. Those are set as workflow inputs in Rewst for the sub-workflow as they are included in the URL for the PUT call.