True Layer Bank Payments Plugin

I have set up the True Layer Bank Payments App, successfully generated the single immediate payment, and returned to my app via the webhook.

The payment doesn’t appear in the True Layer sandbox, though. Should it?

I also tried to generate the get immediate payment info workflow with a view to updating the user balance in my app when the response is returned.

When I run in debug mode step by step it skips over the access token and the documentation is not very informative.

I would be very grateful if anyone can help?