How do I resolve getaddrinfow: The specified class was not found. when trying to call a gRPC function through grpcurl?

I'm currently trying to call a function from a gRPC server using gRPCurl, but I keep getting the following error:

Failed to dial target host "https://server.com": dial tcp: lookup tcp///server.com: getaddrinfow: The specified class was not found.

My grpcurl command looks like this:

 grpcurl -vv -protoset .\Project.protoset https://server.com Namespace/GetNumber

I've tried adding the port number to the URL, but it returns an error saying too many colons. How can I resolve this error? I'm happy to provide more details.