[SOLVED] PC gets stuck on bootloader

did that occur after an installation, or just randomly?

Could be plenty of things. Start with the easy ones.

I suggest first you check whether the keyboard works on a different USB port - particularly one connected directly to the CPU. I'd also try another keyboard or check whether the keyboard itself works - for good measure.

If it's not USB or your keyboard, it's time to plug in a boot stick. Check the drive your bootloader is installed on - SMART status and maybe the partition itself. Maybe your drive or the FS are toast for some reason. If that's the case, try to salvage your data and create a boot partition elsewhere. If not, consider reinstalling your bootloader.

Looks easy enough in your case, since it seems to be systemd-boot? If it is, you basically just need a bootstick with systemd. Then mount the target partition at the right mount point (I think default is /efi) and run bootctl install. See also: https://wiki.archlinux.org/title/Systemd-boot

This SHOUDL only put the binary in the right spot and point the BIOS towards it, but maybe copy the config if you're in there already.

If that still does nothing, maybe try resetting the BIOS. If that doesn't work, try flashing the latest version for your motherboard. (Mind that in most cases that resets all your BIOS settings and might cause new trouble. Maybe also download the last version you know worked as fallback.)

How old is the computer? I had that when tried to install any modern distro on a 20 years old PC