How Do I Trust 3rd Party Apps On IOS?
Tap Settings > General > Profiles or Profiles & Device Management. Under the "Enterprise App" heading, you see a profile for the developer. Tap the name of the developer profile under the Enterprise App heading to establish trust for this developer. Then you see a prompt to confirm your choice.
How do I enable trust on my iPhone?
If you want to turn on SSL/TLS trust for that certificate, go to Settings > General > About > Certificate Trust Settings. Under "Enable full trust for root certificates," turn on trust for the certificate. Apple recommends deploying certificates via Apple Configurator or Mobile Device Management (MDM).
Trust manually installed certificate profiles in iOS and iPadOS
How do I trust a third party app on IOS 15?
Tap on “Trust (Developer Name)”. You'll then you see a prompt to confirm your choice. After you trust this profile, you can manually install other apps from the same developer and open them immediately. This developer remains trusted until you use the Delete App button to remove all apps from the developer.
How to Manually Trust an iOS Enterprise App