Create secure playback stream using Cloud REST API

I need the ability to create streams in wowza cloud using REST API. I need to secure the playback so only authorized users can access the video. How can i do this using REST API ?

I read about token authorization, but unable to see how it can be done using API.

I am in trial mode. Is it the reason ?

Have you tried the process outlined in this article? https://www.wowza.com/docs/how-to-protect-streams-with-token-authorization-by-using-the-wowza-streaming-cloud-rest-api