Beginner API (Service Node) Question

Hello, Completely new with and just trying to have some fun and I ran into a problem.
I wanted to test out a REST call so I made myself a little mock API with and it has a query parameter to get the specific user using User ID.

So the Actual URL for the call is:{“UserID”:1}

Unfortunately, it seems that in the Service Node I always get the regular API call response as if I was calling:

(this one returns a full list)

And I don’t know, perhaps I added the Parameters wrong?
I checked the API with postman and it works as it should, so perhaps I did something wrong here?

Thanks for the help!

Please check this documentation.
Use {{}} / {{context.entities.entityName1}} notations while working with entities.