iOS Beta installation process
Install TestFlight on the iOS device that you’ll use for testing.
Open your invitation email or tap on the public link on your iOS device.
Tap View in TestFlight or Start Testing; or tap Install or Update for the app you want to test.
If you already have the App Store version of the app installed on your device, the beta version of the app will replace that version. When you’ve downloaded the beta app, you’ll see an orange dot next to its name that identifies it as a beta.