How to stop to get a beta iOS build
The very next day after the final release of the new OS for mobile devices, which was held on 17 September, Apple released beta version iOS 12.1 for developers. But among the users there are those who prefer stability and want to stay on iOS 12.
Typically users install the test build to test out new features announced at WWDC. The situation changed after the launch of the final version due to the fact that many want her to stay, because minor updates are not as important as the performance and stability of the OS.
To stop receiving beta updates, you need to go to Settings > General > Profiles and delete the “iOS Beta Software Profile.”
After that, reboot your device and notifications about test more assemblies will not be received.