If I understand your scenario correctly, this is going to be a bit challenging. If you're using an InfoPath form library, then getting the attachment from the infopath from isn't easy, as the file is embedded in the form itself. The solution might be something along the lines of calling an Azure function that programatically retrieves the file from within the infopath form.
Though, is there any reason this was built with an InfoPath library? If you can convert this to a list, and use the list attachment feature rather than the InfoPath attachment feature, then this is a pretty trivial flow to set up. Likewise a button flow can pretty easily capture a photo and get it added to a library, without using InfoPath at all.
