registering webservice loaded as .bpl

I have web services (TSoapDatamodule) loaded as bpl with standalone server
(Dave Nottage sample). When I want to connect with client to this server,
server create error message "No service available for URL ...'.
How to register interface in this sample.

my initialitaion code

  InvRegistry.RegisterInvokableClass(TMainDataModul,
TMainDataModulCreateInstance);
  InvRegistry.RegisterInterface(TypeInfo(IMainDataModul));