IServiceCollection is the application’s registry for services and their dependency-injection configurations. In a gRPC setup, Program.cs uses it to register the framework services needed by the server. section 10.3.4
Registering gRPC services
Add the gRPC services to the collection before connecting the application to the HTTP pipeline: `builder.Services.AddGrpc();`. The related application configuration then maps the implemented `GrpcService` with `app.MapGrpcService<GrpcService>();`. section 10.3.4
builder.Services.AddGrpc();
Use the concise registration listing to verify the service-collection call in Program.cs. section 10.3.4
