Please follow the below steps:
1. Go to Settings>About Phone>Software Info>Build Number and tap 7 times. After "You are in developer mode" appears, please turn on USB debugging in Setting> System>Developer Options>USB Debugging.
2. If the phone is charging, unplug and re-plug the cable. If "USB for Transfer Files" does not show up on the phone, please restart the phone and try again.
3. Try a different data cable to check whether it is caused by the abnormality of the data cable interface.
4. Confirm whether the USB port of the phone is normal, and ensure that the data cable can be inserted regularly.
5. Confirm whether the phone driver software is installed on the computer. If the computer displays a new device prompt when the mobile phone is connected to the computer, it is generally a driver problem. We recommend reinstalling the driver software.
If the issue persists, contact the Nothing Support Team for further assistance.