title: 'Credential is missing' Error On Instantiating S3 Class Using AWS-SDK JS V3
body: <p>I am getting en error when creating S3 client from <code>class S3</code> in newer v3 of aws-sdk javascript.</p>
  <p>I add aws config parameters including credentials obtained from <code>aws sts</code> when user gets authenticated (assuming a role with permission to call <code>getObject</code>) at service-level (when instantiating S3 class) along with other parameters. See my code below:</p>
  <pre><code>const { S3, ... } = require(&quot;@aws-sdk/client-s3&quot;);
  
  someFunc();
  function someFunc(authUserCredentials) {
   ...
   try {
  
     const { AccessKeyid, SecretKey, SessionToken } = authUserCredentials;
     const s3Client = new S3({
                        signatureVersion: 'v4',
                        accessKeyId: AccessKeyId,
                        secretAccessKey: SecretKey,
                        sessionToken: SessionToken,
                        region: 'us-east-1',
     });
  
     console.log(s3Client.config);
     ...
  
   }catch(e) {
       console.error(e);
   }
  }
  </code></pre>
  <p>I checked the <code>class S3</code> code in <code>aws-sdk-js-v3</code> repo, and there doesn't seem to be no 'Credential' constructor config argument required. Am I doing something wrong?</p>