Following worked for me Connect iPhone/Device to mac. Open XCode > Window > Devices and Simulators. Under devices select the "+" icon in the bottom left. Select your device and click Next/Done. On the iPhone make sure you don't have settings open (i.e. force close it.). Open settings > Privacy and Security Scroll to the bottom and Developer mode should now be there. My problem was with step 5, I already had settings open and for what ever reason developer mode wasn't showing so had to exit and reopen settings.