Authentication is the first step in almost all integrations with CXone. In order to use authentication APIs you must have a registered application. The entire process is outlined on the Getting Started.
CXone authentication is based on OAuth 2 and OpenID Connect. In many cases libraries and frameworks automatically support these integrations without your need to directly call any of these APIs. There are other APIs related to discovery that provide additional information for integrations that are also documented here.
Note:For Authentication related (below) APIs having multiple options for post data to API so "Try Out" button not available. However you can see the sample data in response payload.