I've tried in recover mode and Terminaled this cmd: "rm -rf /~username", but it doesn't work..😠
I guess the folder path is not correct, Anyone can help me pls?
You would need to make sure the drive is mounted when in Terminal in Recovery. If the drive is encrypted, you will need to use Disk Utility to mount the drive.
And, as you mention, you would need to know exactly where the file is located on the system while in Recovery as it may not be where it appears. It could be on Macintosh HD or it could be on Macintosh HD - Data (or possibly somewhere else the OS decides to obfuscate).
And, even in Recovery, you may have to disable SIP as HWTech noted. That's not what I would suspect, but the security model could be such that it is required even in Recovery.