Hi there. Thank you for reaching out. The unlocking license can be deleted using the DJI Fly app. Connecting to the aircraft is not required. Simply launch the DJI Fly app. Please refer to the images below.
Step 1: Please click "..." on the top right corner of the APP.
Step 2: Please click "Unlock GEO Zone"
Step 3: Please select the unlock license in the "Account Unlocking Licenses"
Step 4: Please click the check box on the top right corner of the APP.
Step 5: Please select the check box beside the unlocking license, then click the dustbin logo.