Flash firmware from USB without using rescue button?

After breaking my rescue button, I’d still like to flash my MOX to the latest version. Is there a way on Turris OS 4 to flash from USB without using the rescue mode button? As far as I can tell, the manual only describes using the button.

There is a way to manually prepare the SD card for MOX to start from scratch. You can try following it. This should give you a system running the factory image. You will lose all your BTRFS/schnapps snapshots, though.

Alternatively, using a serial cable you should be able to pause the bootloader and execute any commands you want. You can try adding this parameter to the kernel load command: rescue_mode=3 (or 4, I’m not sure about the ±1). This is an advanced procedure and requires that you purchase the serial cable.