@YangTegap if it is stuck at the bootloader unlocked screen, all is not lost. It looks like you were not on the correct Stock ROM. The device has to be on Android 9 for UT to install. Go to XDA- developers forum and search for the correct ROM and you can flash it through fastboot.
If the device sticks at dm-verity, it usually means the battery is on its way out.
Link to XDA forum here.
Flash back to Android 9 and set it up, then start the UT install again.