Identify JsonRpcMethodAttribute on the interface

[ArcticLampyrid]

    public interface IManager
    {
        [JsonRpcMethod]
        public string RegisterApp(string name);
    }
    public class Manager : JsonRpcService, IManager
    {
        [JsonRpcMethod]  // I don't think this is necessary since there is a JsonRpcMethodAttribute on the interface
        public string RegisterApp(string name)
        {
            var token = "abcdefg"; //hard-coded token for test
            return token;
        }
    }

What I use to build a host is

hostBuilder.Register(typeof(Manager));

Version: v0.5.4 (20200621)