All worked out and here’s a functional PowerShell example: https://office365itpros.com/2024/06/17/teams-post-to-channel-workflow/

Right, that example does work and I have used it myself to submit an adaptive card from PowerShell using the Invoke-MgGraphRequest cmdlet. However, it’s a very simple example that isn’t of much use in a real sense. I was looking for something better from the documentation (or in blogs, or wherever) to match the kimd of examples people have written about for the incoming webhook connector. I persist in my quest.

This was very easy for me to find and it works for me.
https://learn.microsoft.com/en-us/microsoftteams/platform/webhooks-and-connectors/how-to/connectors-using?tabs=cURL%2Ctext1#send-adaptive-cards-using-an-incoming-webhook

{
“type”:”message”,
“attachments”:[
{
“contentType”:”application/vnd.microsoft.card.adaptive”,
“contentUrl”:null,
“content”:{
“$schema”:”http://adaptivecards.io/schemas/adaptive-card.json”,
“type”:”AdaptiveCard”,
“version”:”1.2″,
“body”:[
{
“type”: “TextBlock”,
“text”: “For Samples and Templates, see [https://adaptivecards.io/samples](https://adaptivecards.io/samples)”
}
]
}
}
]
}

This is just a sample and it worked. I plugged this into the schema in Power Automate. For the “post message to teams”, I chose the “text” element. Power Automate created 2 nested for loops for me automatically for the “attachements” and “content” arrays.

Yep. Tried that. There’s a dearth of documentation on this point as to exactly what the input is to post to the URL. I’ve been chatting with some folks in Microsoft about this to see if better and more complete documentation can be produced.

Management…