title: Send SMS with Amazon SNS
body: <p>I am trying to send SMS through the AWS SNS using the SDK for php.</p>
  
  <p>I already configure the user in IAM (created a user to do this), grant full access to SNS service and check the keys many many times.</p>
  
  <p>I am using the code that was posted in this topic for testing <a href="https://stackoverflow.com/questions/38752336/sending-sms-with-amazon-aws-services-php">link</a> and receiving this message error</p>
  
  <blockquote>
    <p>Fatal error: Uncaught exception 'Aws\Sns\Exception\SnsException' with message 'Error executing "Publish" on "<a href="https://sns.us-east-1.amazonaws.com" rel="nofollow noreferrer">https://sns.us-east-1.amazonaws.com</a>"; AWS HTTP error: Client error: <code>POST https://sns.us-east-1.amazonaws.com</code> resulted in a <code>403 Forbidden</code> response:   Sender SignatureDo (truncated...) SignatureDoesNotMatch (client): The request signature we calculated does not match the signature you provided. Check your AWS Secret Access Key and signing method. Consult the service documentation for details</p>
  </blockquote>
  
  <p>Anyone knows what I am doing wrong? I am not able to find the solution </p>