Close chromium auto start

Hi, I have select chromium as auto start in dietpi. When the dietpi boots it goes straight to the browser. However I cannot close the chromium and go to Linux terminal. Please help me out as I am stuck in chromium. I have tried alt+f4 but nothing happens. Appreciate the help in this regard.

Hi,

I did a test on my RPi3B+ and I could close Chromium without issues using ALT+F4 (keyboard directly attached). Another option is to connect via SSH and kill the running process or to change AutoStart option followed by a reboot.