Hi @Anonymous,
Just to double check, you mean to notify in a private teams chat, correct?
If so, you could replace the post your own adaptive card as the Flow bot to a channel action by a Post adaptive card in a chat or channel action. You can then reuse the Created By property of the work item to send it to the correct recipient.
Below is an example of that approach.
1. Add a Post adaptive card in a chat or channel action. I used the following expression in the Recipient field to retrieve the email address of the CreatedBy field from Azure DevOps.
split(split(triggerOutputs()?['body/fields/System_CreatedBy'], '<')[1], '>')[0]
