Linux Shout published four ways to install GIMP on Ubuntu 22.04 LTS Jammy.
4 Ways to install GIMP on Ubuntu 22.04 LTS Jammy
Install free and open-source GIMP editor on Ubuntu 22.04 Jammy JellyFish Linux for editing, retouching, or optimizing your images.
4 Ways to install GIMP on Ubuntu 22.04 LTS Jammy