As far as I can tell, there is no permission for form-approval. It would be useful if users could be given the permission to only approve or deny a form-submission, rather than being assigned as administrators.
There is an approval workflow feature in the most recent release (v 11). Is that what you need?
Yes, but it is only available for users with the role Administrator. There is no permission which grants the Approval-role for the form: https://i.snipboard.io/NA7Trz.jpg