eglot for C#, find references, implementation, declaration

Question

As I've switched to eglot now, what is the proper way to find references, implementations and declarations?

I tried xref-find-references, but it only returns "user-error: No references found for: LSP identifier at point", so not really sure what packages to try?

EDIT: I found eglot-find-[declaration,implementation,typeDefinition], but it gives me:

eglot--error: [eglot] Sorry, this server doesn't do :textDocument/declaration

EDIT: ok, I have this test code:

   1 namespace test.eglot
   2 {
   3     class Hukarz
   4     {
   5         public static void Main()
   6         {
   7             IFoo xyzzy = new Foo();
   8             System.Console.WriteLine(xyzzy.Bar());
   9         }
  10     }
  11 
  12     public interface IFoo
  13     {
  14         public string Bar();
  15     }
  16 
  17     class Foo : IFoo
  18     {
  19 
  20         public string Bar()
  21         {
  22             return "quux";
  23         }
  24     }
  25 }

If I have point on line 7, on IFoo, and eglot-find-declaration, it says:

eglot--error: [eglot] Sorry, this server doesn't do :textDocument/declaration