// inherit AlertServiceBase
 public class AlertServiceImpl : AlertService.AlertServiceBase
 {
     // write customize  logic for the method
     public override Task<AlertResponse> SendAlert(AlertRequest request, ServerCallContext context)
     {
          // print out want we recieved from request
          Console.WriteLine($"[Alert Request], {request.DateTime}, Uid = {request.Uid}, Message = {request.MsgValue}.");

          // do something .... and response
          var response = new AlertResponse()
          {
              Ack = request.Uid,
              ReturnCode = ReturCodeEnum.Checking.ToString(),
          };

         return Task.FromResult(response);
     }
}


public enum ReturCodeEnum
{
    Release,
    Checking,
    Reboot,
}