How can I prevent someone from spamming my rankings?

I made a code that sends and receives firebase data, according to the score, but how to prevent users from putting "inappropriate" words as name? and that they keep sending scores every second?

As for the inappropriate words, you'll have to filter them out somehow. This has always been a little bit tricky, as people like to get creative with stuff like A$$ or A.S.S and such. Also you have to avoid filtering out common words like ASSemble just because they contain a no-no word. There's probably some libraries out there (https://www.npmjs.com/package/bad-words) or javascript code (https://stackoverflow.com/questions/56456144/javascript-simple-profanity-filter) but ideally you'd do that server-side and not client-side.

And for sending scores every second, it depends a little on how the game is designed. But if you could e.g. only allow to send the score if it's a new highscore. Or there is some kind of timeout. Or it's only possible to send the score after a finished game.

As for the inappropriate words, you'll have to filter them out somehow. This has always been a little bit tricky, as people like to get creative with stuff like A$$ or A.S.S and such. Also you have to avoid filtering out common words like ASSemble just because they contain a no-no word. There's probably some libraries out there (https://www.npmjs.com/package/bad-words) or javascript code (https://stackoverflow.com/questions/56456144/javascript-simple-profanity-filter) but ideally you'd do that server-side and not client-side.

And for sending scores every second, it depends a little on how the game is designed. But if you could e.g. only allow to send the score if it's a new highscore. Or there is some kind of timeout. Or it's only possible to send the score after a finished game.

is there a way to log in with a social account to save the ranking? facebook example

then I would get the person's facebook name

Firebase has a login system with Google accounts.

How do I organize my code to get only the top 10 scores?