Adaptive Cards with Incoming Webhooks in Outlook

Hello,
I am trying create adaptive card on outlook. I created group, I added incoming web hook. Problem is that I get this error message "Summary or Text is required." when I call it from postman. I had same

problem in Teams where I solved it by:

{
  "type": "message",
  "attachments": [
    {
      "contentUrl": null,
      "contentType": "application/vnd.microsoft.card.adaptive",
      "content": {
        "version": "1.2",
        "$schema": "http://adaptivecards.io/schemas/adaptive-card.json",
        "type": "AdaptiveCard",
        "body": [
          {
            "type": "TextBlock",
            "text": "For Samples and Templates, see [https://adaptivecards.io/samples"
          },{
            "url": "https://adaptivecards.io/content/cats/1.png",
            "type": "Image"
          }]
      }
    }]
}

Problem is that it does not work for outlook. Do you have any idea? What can I do?

Thank you for your help