The "Settings" app on Android includes a feature called Developer Options. The phone needs to turn on this function to use USB debugging to connect to AGB.
Settings> System> About Phone> Version Number, click the Version Number option 7 times
Go to the Developer Options page and turn on USB Debugging
- Android 9 (API level 28) and higher: Settings> System> Advanced> Developer Options> USB debugging
- Android 8.0.0 (API level 26) and Android 8.1.0 (API level 26): Settings> System> Developer Options> USB debugging
- Android 7.1 (API level 25) and lower: Settings> Developer options> USB debugging
The steps to open the developer option are slightly different for each brand of mobile phone. The above is a general step. If it still fails to open, please search the Internet for the opening steps of the corresponding brand.