itch.io

Ok, here should be everything you need, just follow instructions under Ubuntu / Debian-based Linux category

https://www.gbstudio.dev/docs/installation/

EDIT:

In line :

sudo dpkg -i gb-studio_1.0.0_amd64.deb

change the "gb-studio_1.0.0_amd64.deb" to current .deb file name that you have