
H,
I have a child flow that retrieves an attachment from a form, and needs to use it as an output parameter so that the parent flow uses it and sends it by mail, but I don't know how to use the "Respond to a powerapps or flow" to retrieve my attachment which ends up inside a loop
Since you are creating an array of files I don't think you will be able to use Respond to Power Apps or flow to return the array. You'll need to use HTTP response instead.