How to update user with displayName

Documentation is here

let changeRequest = Auth.auth().currentUser?.createProfileChangeRequest()
changeRequest?.displayName = displayName
changeRequest?.commitChanges { (error) in
  // ...
}

When you want to change the details of a user in Firebase, you want to use FIRAuth.auth().currentUser.profileChangeRequestin order to update any details other than the user's email and password. To update their email or password, you need to use a specific method for each. updateEmail and updatepassword