How come I cannot see my data when calling the API in the developer portal?

To communicate with the API, you need to identify your application. This is possible by using your client id and client secret (see client credentials). These are linked to an integration 'Partner' to make sure data from one partner cannot be accessed by another partner.

When using the API developer portal and its built-in client id and secret, you are connected to a dedicated partner linked to this API developer portal. This means you can only access data created in the API developer portal.