Auth0 lock with additional SignUp Fields

lock.js

    // Available Lock configuration options: https://auth0.com/docs/libraries/lock/v11/configuration
    var lock = new Auth0Lock(config.clientID, config.auth0Domain, {
      ...,
      additionalSignUpFields: [{
        name: "phone_number",
        placeholder: "Enter your phone number",
        // The following properties are optional
        validator: function(phoneNumber) {
          return {
            valid: phoneNumber.length >= 10,
            hint: "Must have 10 or more digits" // optional
          };
        }
      }],
      ...
    });