Help with posting a mod Thread

I've created a mod for Alien Isolation that I have always used privately, but want to upload due to the game being free for the week on Epic. However, when I go to upload it, I get a message saying "The developer (Creative Assembly) only allows members to connect it with mods". I thought I was a member? Help!

-Maybe you are not a member of their limited member group(invitation only). What happens with option "other" in that menu.