Pleaceholders not working on new workflow "Post a adaptative card to channel" on MS Teams

Question

I created a workflow "Post to a channel when a webhook request is received"

With second action: Post card in a chat or channel

In the Adaptative Card i had a placeholder ${summary} but when i sent the JSON messsage you see attached what i got in the channel is this. Can anybody help? Why placeholders are not working ?

{
  "@type": "MessageCard",
  "@context": "http://schema.org/extensions",
  "themeColor": "0076D7",
  "summary": "meta-search-google.prod-nordics",
  "sections": [
    {
      "activityTitle": "New revision detected, progressing canary analysis.",
      "activitySubtitle": "meta-search-google.prod-nordics",
      "facts": [
        {
          "name": "Target",
          "value": "Deployment/meta-search-google.prod-nordics"
        },
        {
          "name": "Failed checks threshold",
          "value": "1"
        },
        {
          "name": "Progress deadline",
          "value": "180s"
        },
        {
          "name": "Traffic routing",
          "value": "Blue/Green"
        }
      ]
    }
  ]
}