Describe your environment

• Operating System version: macOS Monterey 12.0.1
• Firebase SDK version: 9.10.0
• Firebase Product: auth
• Node.js version: 12.22.3
• NPM version: 6.14.13

Describe the problem

I receive the following error when creating a user with phoneNumber: null:

FirebaseAuthError: The phone number must be a non-empty E.164 standard compliant identifier string.

But the function params say it should be allowed:

Steps to reproduce:

Run the code below.

Relevant Code:

import firebase from 'firebase-admin'

await firebase.auth().createUser({
  displayName: 'John',
  email: 'john@example.com',
  phoneNumber: null,
})