The Xcode developed application cannot be tested on the actual iPhone.

The Xcode developed application cannot be tested on the actual machine.

Several people are developing an application using Xcode.
The source code is managed by git and cloned to each Mac.
The administrator of Git has been able to test the actual machine (iPhone), but the other members will be "Build failed".(Connecting Mac to iPhone via wire)
I can build it without any problems with the simulator on my Mac.

I have no plans to publish it in the Appstore, so I have not registered with the Developer Program.

Why?