To learn more about the SMS API, visit the SMS section of the Sinch Developer Portal where you learn:
If you still have questions or need support please contact Sinch.
Learn how to get started with SMS by watching this step-by-step tutorial. The video explains the basics of SMS and shows you how easy it is to send your first message with Sinch:
Sign up to the Sinch Dashboard and get started today or take a look at the Sinch SMS Product page to learn more about our SMS products.