How do I turn off Communication Safety on iPhone 15 Pro?

I suspect you are in the EU or other region that requires an Age Assurance check. Until that is done, you will not be able to turn off Communication Safety. Check under your Apple Account name when opening Settings for any warnings. If you already done the Age Verification, then Force Restart your phone:

• Press and quickly release Volume Up
• Press and quickly release Volume Down
• Press and HOLD Side button until the Apple Logo appears. This could take up to 15 seconds while holding the side button and you will have to ignore anything else on the screen including the prompt to Slide to Power Off. If you don't see the Apple Logo while holding the Side button, then try again as it may take a couple of attempts to get the speed and sequence correct.

• What region are you in?
• Do you have any warnings under your Apple Account name when opening Settings?
• What is the Year for your birthdate at Settings > [name on top] > Personal Information > Birthday? Don't need your actual birthday, just the year.