Iphone IOS 13.1 Loads my app but wants me to approve it in Document manager.

I've developed an app to loop my insulin pump, continuous glucose monitor and Iphone together using format from LoopDocs.org. The app develops fne on Xcode and downloads to the phone, but i get message on phone, "unapproved developer. Set permission at settings-general-device manager. No such location on the phone, at least none that I can find. Any suggestions??