Patch the boot image (requires Python script) – you can run Magisk patcher via Termux using unzip and magiskboot binary (extracted from Magisk APK).
git clone https://github.com/Benjamin-Dobell/Heimdall.git unlock bootloader via termux
Once the process finishes (it takes 2-10 seconds), reboot your unlocked device: Patch the boot image (requires Python script) –