Saving Data for Each User

Hi all,
I’m currently making a to-do list app, and I currently have it so that the user can sign in and sign up (which I created using Chris’ tutorial on Firebase authentication). Right now, I figured out how the user can save lists to their device but not their account, meaning there’s really no point in signing in and out. The reason why I want there to be accounts is so that the user can sign in on different devices but access the same list and so users can share and edit their friends’ lists. Does anyone know how to get the data saved in Firebase for each account and not on the device?
Thanks!

@Star123
You’ll need to upload the data to Firebase database or Firestore (just another kind of Firebase database)

You should probably look into how to organize Firebase data. You’ll have to figure out the proper schema (or organization system) to use so that only the allowed users can edit certain lists.

Look into how to structure No-SQL data