bootloader is the component or code in the operating system that is executed before the start of any android device. if you have a unlocked bootloader device & you want to lock it again then you can do it by following below Instructions.
Requirement:
- charge device 60%
- PC with platform tools
Steps:
- flash global or chines firmware you needed
- Put phone t fastboot mod
- connect it to computer using usb cable
- pen cmd in platform tool folder
- now send below code
fastboot flash lock
- on phone confirm lock warning, once done, it will be reset and restart!