turning find my iPhone off

Remove an iOS device or Mac

• On an iOS device: Go to Settings > [your name] > iCloud, then turn off Find My [device]. Enter your Apple ID password, then tap Turn Off.

If you’re no longer using an iOS device, an Apple Watch, AirPods, or a Mac, you can remove it from Find My iPhone using Find My iPhone on iCloud.com or your device. When you remove a device, it’s removed from your Find My iPhone Devices list, and if your device has iOS 7 or later installed, Activation Lock is also turned off.

iCloud: Remove your device from Find My iPhone - Apple Support

https://support.apple.com/kb/ph2702