All credits goes to Peep and his guide available here : https://www.reddit.com/r/glorious/comments/okrbjg/peeps_qmk_and_via_rgb_guide_only_for_ansi/
The only real value of this page is to provide a firmware already compiled : download.
Just flash it with QMK toolbox.
you will need to load the iso layout (made by inffy from the glorious discord) separately in order to have a json layout with VIA :
for reference, here’s the keymap.c file :