How can I write unit tests for angular's HttpClient with Jasmine Marbles?

I have a project where I extensively use angular HttpClient requests as a basis for streams. I would love to test these requests using jasmine marbles, as it seems to be 'industry standard' for unit testing of streams.

I am however struggling with getting the whole thing to work, either the HttpTestingController fails, or the marble fails. I have built a stack blitz to demonstrate my point.