got it working. oneplus 8 pro was on 13. easy installer requires Android 11.
1 step. downgrade to 12
https://www.youtube.com/watch?v=IN3eJpkgB1o
2. step downgrade to 11
https://techibee.in/rollback-downgrade-packages-for-every-oneplus-device-from-oxygenos-12-to-oxygenos-11/
3. on Android 11 FRP prevented the changes in the developer settings
https://www.youtube.com/watch?v=3obgT7faEGc
4.easy installer works fine.
EDIT: … and installed via windows update the android driver