Versioning example

The examples lack of sample about service versioning on server.
Currently I am working on PoC of versioning and there is only "theory" here: https://docs.microsoft.com/en-us/aspnet/core/grpc/versioning?view=aspnetcore-3.1

and here https://developers.google.com/protocol-buffers/docs/proto3#packages

Is there any sample that you could share?
Like package Greet.v1; and package Greet.v2;

Thanks,
Piotr Kowalski