The terminal cannot start

If koma tells you it cannot prepare the terminal, this computer could not start the new one. The usual cause is a machine that does not meet the requirement: macOS 13 or newer, a current Linux, or Windows 10 or newer.

You can still open the older terminal:

koma legacy

That older window is a fallback. This book describes the terminal you get from koma on its own. Use the older one only until this computer can start the new one.