title: AWS SNS Invalid parameter phone number
body: <p>i am trying to learn aws sns service to send sms from my web application.
  I am working on localhost.</p>
  
  <pre><code>$params = array(
      'credentials' =&gt; array(
          'key' =&gt; 'iam_key',
          'secret' =&gt; 'iam_secret',
      ),
      'region' =&gt; 'ap-south-1', // &lt; your aws from SNS Topic region
      'version' =&gt; 'latest',
      'http' =&gt; ['verify'=&gt;false]
  );
  $sns = \Aws\Sns\SnsClient::factory($params);
  
  $msgattributes = [
          'AWS.SNS.SMS.SenderID' =&gt; [
              'DataType' =&gt; 'String',
              'StringValue' =&gt; 'Klassroom',
          ],
          'AWS.SNS.SMS.SMSType' =&gt; [
              'DataType' =&gt; 'String',
              'StringValue' =&gt; 'Transactional',
          ]
      ];
  
  $payload = array(
          'Message' =&gt; "HK test",
          "PhoneNumber" =&gt; "1234567890",
          'MessageAttributes' =&gt; $msgattributes
      );
  
  $result = $sns-&gt;publish($payload);
  </code></pre>
  
  <p>i want to send sms directly on number. this code is giving this error</p>
  
  <p>Fatal error: Uncaught exception 'Aws\Sns\Exception\SnsException' with message 'Error executing "Publish" on "<a href="https://sns.ap-south-1.amazonaws.com" rel="noreferrer">https://sns.ap-south-1.amazonaws.com</a>"; AWS HTTP error: Client error: <code>POST https://sns.ap-south-1.amazonaws.com</code> resulted in a <code>400 Bad Request</code> response:   Sender <Code>InvalidPara (truncated...) InvalidParameter (client): Invalid parameter: PhoneNumber Reason: +1234567890 is not valid to publish to -   Sender <Code>InvalidParameter</Code> Invalid parameter: PhoneNumber Reason: +1234567890 is not valid to publish to  13e181c2-a20f-5e77-9c8e-d38c55c50266  ' exception 'GuzzleHttp\Exception\ClientException' with message 'Client error: <code>POST https://sns.ap-south-1.amazonaws.com</code> resulted in a 400 Bad Request</code></p>
  
  <p>i don't know why....</p>