how can make leaderboard to country in web game?
Its not that simple - you’ll need to keep tabs of what country the player is from. Either by asking them, or from their IP address (neither of which is a fool proof way).
You should be storing all the scores and player details in a database. Then do a select on player details, group by country, summing the scores in each group and order by score summation.
Is it possible to do this with the firebase?
Possibly. Check this thread, and also do a search for GDevelop Firebase and see how those results help.
i will try