“Insertable” Database

Hello! Its been a long while since i last made a question here but im planning on using gdevelop seriously again.

While i am still trying to make an multiplayer supported rpg game, im trying to start with the important things first like data.

While i saw a video for how to incorporate a database ingame, all i need to know is whether the following is possible:

1.) players making an account and putting their own database with a password (as in, the game itself will have a firebase, but the players can have their own firebase account for their own personal gameplay data)

2.) if its possible: how can the game take out the data from said player’s database

3.) how can players likewise save the specific data from the game (like the character, their stats and class aswell as their items and skills)

The only data that is going to be saved is textbased as since its an rpg all i need for it to be saved is the data like player’s characters’s stats and status and inventory. I know i can make the game’s own databade save the data itself but i dunno if it would make the database fill up quickly and thus prevent the game from saving more data. Therefore, the idea is that the game’s database instead saves the player’s account and other important info and game data that is important to the game that is not player related.