Ty both. FruityTrey for asking what I was going to ask, Y Press for answering why I couldn't find the DLC on steam lol
It's live now:
https://store.steampowered.com/app/1686740/Alpha_Hole_Prison__RinTimbers_Perspective/
Downloaded it. Need to "unlock it" (find the path that won't spoil the story) but I will find it in the end. Ty for the update
