OAuth is an authorization protocol used mostly in scalable web applications. The latest version is the 2.0, which uses tokens to access your data in another system.
Official reference guide
Have a look at the OAuth2 protocol official guide on RFC6749
WARNING The auth scope needs to have
For follow the correct OAuth2 flux, you need a client_id to authenticate your app, you can get one client per account. View in Create partner. You can also create a oauth client in the dashboard