To obtain an OAuthClientId, OAuthClientSecret, and CallbackURL, you first need to create an app linked to your Asana account.
To create an app linked to your Asana account:
- Log in to your Asana account.
- Navigate to My profile Settings > Apps > Manage Developer Apps or https://app.asana.com/0/developer-console.
- Under My apps, select New app. Specify the app name, then select Create app.
- Once your app created, set Redirect URL to http://localhost:33333 (or a different available port of your choice), then select add.
Once you are done with creating a new app, it will be displayed on your screen. From there, you can click View Client ID to reveal your newly created app's OAuthClientId and OAuthClientSecret.