title: cognito pool - failed to signup a user
body: <p>I am trying to build a user management based on cognito user pool.
  I am using nodesjs + express for the backend, all the operation to cognito will be done from the nodejs.</p>
  
  <p>my signup route is</p>
  
  <pre><code>app.post('/signup', (req, res) =&gt; {
  let userName = req.body.userName;
  let email = req.body.email;
  let familyName = req.body.familyName;
  let password = req.body.password;
  
  let attributeList = [];
  
  let dataEmail = {
      Name: 'email',
      Value: email
  };
  
  let name = {
      Name: 'name',
      Value: userName
  };
  
  let familyname = {
      Name: 'family_name',
      Value: familyName
  };
  
  let attributeEmail = new AmazonCognitoIdentity.CognitoUserAttribute(dataEmail);
  let attributeName = new AmazonCognitoIdentity.CognitoUserAttribute(name);
  let attributeFamilyName = new AmazonCognitoIdentity.CognitoUserAttribute(familyname);
  
  attributeList.push(attributeEmail);
  attributeList.push(attributeName);
  attributeList.push(familyname);
  
  let userPool = new CognitoUserPool(poolData);
  userPool.signUp(email, password, attributeList, null, (err, result) =&gt; {
      if (err) {
          console.log(`got error during signup ${err}`);
          res.sendStatus(500);
      } else {
          let cognitoUser = result.user;
          console.log('user name is ' + cognitoUser.getUsername());
          res.sendStatus(200);
      }
  
     });
  
  });
  </code></pre>
  
  <p>however I am getting a failure and cannot find how to over come it
  the error is missing parameter: </p>
  
  <p>got error during signup MissingRequiredParameter: Missing required key 'Username' in params</p>