title: How to send a message to Whatsapp using Spring Boot?
body: <p>I have some questions:</p>
  <ol>
  <li><p>How to send a message to Whatsapp using Spring Boot? Is there an API ready to be used?</p>
  </li>
  <li><p>Is the traffic of the message, whether for receiving or sending, is paid? If so, how does the payment for this service, charged by characters or bit size of the information?</p>
  </li>
  </ol>