The "flashing lock" error only appears when you are in Fastboot (Bootloader) mode. To get back there after enabling the settings above:
If you receive an "unknown command" error, try the legacy command: fastboot oem unlock 4. Confirm on the Device
Try the modern standard command first: fastboot flashing unlock The "flashing lock" error only appears when you
Modern Android security prevents unauthorized software changes unless the "lock flag" is explicitly flipped by the user. Here is how to fix this and successfully unlock your device. 1. Enable OEM Unlocking
You cannot unlock the bootloader through a computer alone; you must first give the phone permission from within the Android OS. Open > About Phone . Here is how to fix this and successfully unlock your device
Connect your phone to your PC and run: adb reboot bootloader
Once the device is in Fastboot mode and connected to your PC, use the following commands. . Open > About Phone
Also, enable to allow the computer to send commands. 2. Enter Fastboot Mode