how to send data to "on user creation" server function?

i'm writing a server function that'll create a doc in "Users" collection on each user creation. but i wanna collect and store more data from the user. maybe their city, zip code and stuff. so how can i send those data to my function so that i can store those in the doc? I'm using email-password based login

how to send data to "on user creation" server function?

I would suggest creating the account with a function the user executes rather than using account.create() and a function triggered by event

then what difference it would make if we do account.create() and then databases.createDocument() in the client side directly?

Consolidating the API call and making sure to do validation

about consolidating the API calls, even if we do it in the server function, we still need to do account.create() and then databases.createDocument(). don't we? so are the API calls really getting consolidated?

and about validation, is it safer for any task to be done in the server function compared to the client side?

There consolidated on the front end

If you need validation, yes, use function