I want to login users with LoginWithCustomID function but before that I want to do some if conditions on server side before logging them in.I have a function that does this verification but for the time being it is on client side and can it be bypassed easily I want that method to be on server side.So each time someone logins I want that method to be called. So that server/cloudscript does that verification and if it fails user won't be logged in. else users can login as usual.