Using user UUID on other StoryBoards! Help!

Hi, i am developing an iOS App like memorizing english words.
My problem is when the user login on iOS App login screen, the user actually has an UUID, and i cant use this UUID for other story boards,
i want
api/user/USERID/words like
localhost:8080/api/users/E5908DF4-6E36-44A6-B3A6-CBE205C15AF1/words
how can i access this UUID from login page and how can i save the UUID,
our book has an optional in UUID?
when i save this UUID to userDefaults and use it from other story boards, i get nil error, because i can not create UUID in login page, but the backend does.

How can i use user UUID?
Thanks

@erdmzgr If I understand correctly, you have a couple of options. If you want to keep the routes the same you need to return the user ID after login and save that in the keychain or user defaults etc so you can use it later. The other option is you can create a new route, /api/users/me/words to get the works for the logged in user - does that help?