All you can do is press and hold the power button until the computer powers off. Give it at least 30 secs then power on again and hope it will recover Windows 10.
If it doesn't then you will need another windows PC to create a Windows 10 boot USB (if you haven't already got one)
Download Windows 10 (microsoft.com)
Boot from the new created USB and se if any of the repair options help fix the looping.
It sounds like Windows 11 upgrade cannot complete and it is trying to recover Windows 10. Do you have a backup of your personal files?