Проблема с completeNewPasswordChallenge

Question

Я получаю следующую ошибку:

TypeError: Невозможно прочитать свойство 'completeNewPasswordChallenge' из неопределенного.

После моего кода

login(Email, Password) {
    var authenticationData = {
      Email,
      Password
    };

    this.cognitoUser = this.getCognitoUser(Email);
    let authenticationDetails = new AuthenticationDetails(authenticationData);
    return new Promise((resolve, reject) => {
      this.cognitoUser.authenticateUser(authenticationDetails, {
        onSuccess: function(result) {
          this.setCredentials(result.getIdToken().jwtToken);
          resolve(result);
        },
        onFailure: function(err) {
          reject(err);
        },
        newPasswordRequired(userAttributes, requiredAttributes) {
          debugger;
          console.log("newPasswordRequired()");
          console.log(userAttributes, requiredAttributes);
          this.cognitoUser.completeNewPasswordChallenge(
            Password,
            {},
            authenticationData
          );
        }
      });
    }).then(() => this.getUserData());
  }