Save and get user data with Firebase

I have this big issue with a Global Structure Variable called “Saves” where is stored all User data, but I can’t put this Structure Var in the Firestore Database because there isn’t an expression to take these Var, so what i can do now? When i try to put it in other ways it just come a String Variable called [Structure]

I just want to create a system where the user can save all their data on the cloud, and all data are stored in a single Structure


For some reason Firebase of Gdevelop doesn’t reas the Global variables