@MrT10001 sorry my bad, I wrote redmi note 9 lavender, but it's redmi note 7.
I hadn't lock anything (intentionally), so if the system didn't, I didn't.

adb doesn't work, obviously, so I can't install any other android based distro. (Is there any alternatives cmd for ubuntu touch?)
I've also tried to reset the phone (redmi note 9 lavender) to the factory options but doesn't work.
Fastboot doesn't show anymore the classic image (this one below)

but a full black screen, and recovery options are not anymore the android options, but (I guess) the ubuntu touch options. There's lineageOS logo, but with ubuntu colors and 3 buttons: reboot, factory reset and advanced. In the bottom of the screen there's a label "halium 9".

I tried to install twrp, but doesn't work. The recovery remain the same. Please help because I have finished idea about...
My theory is that ubuntu touch has placed some "lock" somewhere, like android do with bootloader, but Idk guys, please help me.