Sender.cs

    [ClientMetadata("email")]
    public class EmailSender : ISender
    {
        public Task Send(string message)
        {
            // Sending message to client

            return Task.CompletedTask;
        }
    }
    
    [ClientMetadata("sms")]
    public class SmsSender : ISender
    {
        public Task Send(string message)
        {
            return Task.CompletedTask;
        }
    }