Before we can get into the RingCentral APIs, we got to setup a RingCentral app in the developer portal. This helps us get the Authorization info we need
Time for me to cop out!!
I know I've done some pretty decent tutorial level blog posts here, but for this next piece, there's so many existing tutorials and posts, that I feel safe bowing out.
Go to this web page, https://developers.ringcentral.com/guide/basics/explorer#create-app-instructions
Then click "Show detailed instructions".

Follow those.
When you're done, you need to grab a few things from the RC App Console.

Keep track of the API server URL, client ID and secret, and account login and password. When you make an app, a sandbox RC account is created. You'll need all those pieces of information to start playing with the RC SDKs