I can't access custom attribute in dispatch proxy invoke method in .netcore6

Question

I cannot access the custom attribute I wrote for the method within the invoke method.

Attribute class :

public class HttpTypeAttribute : Attribute
{
    public string Type { get; set; }
    public HttpTypeAttribute(string type)
    {
        Type = type;
    }
}

Web function:

 [HttpType("POST")]
    public ResponseDTO Run(RequestDTO requestDTO)
    {
        var result = ProxyManager<TestInterface>.CreateProxy(url).Run(requestDTO);
        return result;
    }

Invoke method:

public class ProxyManager<T> : DispatchProxy where T : class
{ 
    public string APIAddress { get; set; } 
    public static T CreateProxy(string APIAddress)
    {
        var proxy = Create<T, ProxyManager<T>>() as ProxyManager<T>;
         
        proxy.APIAddress = APIAddress;
        return proxy as T;
    }

    protected override object Invoke(MethodInfo targetMethod, object[] args)
    {
          //attr is null . I can't access custom attribute
        HttpTypeAttribute attr = (HttpTypeAttribute)targetMethod.GetCustomAttributes(typeof(HttpTypeAttribute), true).FirstOrDefault(); // attr is null
        string url = APIAddress;
        url += targetMethod.DeclaringType.Name + "/" + targetMethod.Name;

        var returnStr = HttpRequest.HttpPost(url, args);
        return JsonSerializer.Deserialize(returnStr, targetMethod.ReturnType);
    }

}

Is there any way to do this? I would be glad if you help.