Adding a Mountebank proxy imposter for graphql service virtualization

Question

Has enyone used Mountebank proxy for virtualisation of a graphql endpoint?

I've used the plugin: https://github.com/basharat-j/mb-graphql

But, I can't figure out how to configure the proxy imposter. Do you guys have any good ideas, or suggestions?

I have installed as well as run the mb-graphql docker image. I'm not able to configure the imposter to work as a proxy.