When you click subscribe, launch the game. Load or create a character and when you're in the game just right-click anywhere and the menu should be in the context menu that pops up.

The menu doesn't open when i do that either

same here

Same problem :/

It's not opening for me too

nvm I found out the problem, I didn't activate the mod ;)

how to activate?

You activated the mod in MODS?