If you're building and integrating your own app with Rebrandly, you'll start by generating the client IDs from within your Rebrandly account.
To generate the IDs:
Log in to Rebrandly.
Click Integrations in the top navigation menu.
Scroll down and click Build with us.
Enter the Application name and Redirect URL where your app is hosted.
Click Save.
Click Generate Credentials.
Copy your Client IDs for use.
You can now click MyApps in the top navigation menu to view your apps.
Follow the guide on Oauth Flow in the Developers Hub to finalize the authorization for the integration with Rebrandly API.