Turn off beta updates
For devices running iOS 16.4 or later:
To stop receiving betas, go to Settings > General > Software Update > Beta Updates and tap “Off” from the list of options.
For devices running iOS 16.3 or earlier:
Go to Settings > General > VPN & Device Management and tap the iOS & iPadOS Beta Software Profile that appears.
Tap Remove Profile. If asked, enter your device passcode, then tap Remove. Once the profile is deleted, your device will no longer receive iOS betas.
Install the next version of iOS
When the next commercial version of iOS is released, you can install it from Software Update.