In your App Dashboard, under Add Products to Your App, find Commerce in the list of products, and click Set Up.
If you don't have a business account yet, in the dropdown, choose Create a Business Management.
After you have set up a test commerce account, placed a handful of test orders in your test Page Shop, and generated a page access token, you can start the integration work and call Commerce API endpoints.
The Developer Performance Dashboard provides a quick way to monitor the status of your integration. You can use it to get a snapshot of the number of API calls your app has made, the success rate of those calls, error rates and other data. To access it, in the left navigation menu in the App Dashboard, look under Commerce and select Dashboard.