How to get a token?

I am using postman to try and get a token from the sandbox container I have spun up successfully.

what are the credentials for this sandbox system please?

I observed the below but it suggests either its already generated or its a concatenation of the sandboxes Mail box ID, etc? If so, where would I find this info please.

Message Exchange for Social Care and Health (MESH) API - NHS Digital

resolved by reviewing python code