Understanding the parameter RequestData in the method InvokeRPC call

We have a use case where we are developing an observability platform, where users define their own sources, which are different gRPC endpoints with different structures.

The platform that we are building should be able to fetch the dynamic gRPC endpoints and figure out the proto files dynamically, and we came across https://github.com/fullstorydev/grpcurl which exactly solves our purpose.

The only issue is when we are triggering InvokeRPC, I'm unable to understand what needs to be given in requestData. Could you please help with a small example on how to trigger InvokeRPC, that would be of a great help to us.

Thanks,
Ravikanth