Open the Settings app
Tap Privacy & Security
Tap Location Services
Toggle Location Services to On
If prompted, choose Allow or Allow While Using depending on your preference
(Optional) Tap an app under Location Services
Select Never, Ask Next Time, While Using the App, or Always
(Optional) Turn on Precise Location for apps you want to share more accurate location with
(Optional) Under Location Services, enable System Services options you want (e.g., Emergency Calls & SOS, Find My iPhone)