How to add signup validation on backend

I have added new validation fields and rewrite the frontend version of signup proccess and now I am trying to add validation on backend in

defineUserSignupFields

defineUserSignupFields

but it does not work, how can I achieve validation on backend? Maybe there is a way overwrite just

ensureValidArgs

ensureValidArgs

function?

function ensureValidArgs(args: unknown): void {
  ensureValidEmail(args);
  ensurePasswordIsPresent(args);
  ensureValidPassword(args);
}

function ensureValidArgs(args: unknown): void {
  ensureValidEmail(args);
  ensurePasswordIsPresent(args);
  ensureValidPassword(args);
}