Send message to my linkedIn connection using Mathematica 10.3

I am trying to send message to my LinkedIn connection using Mathematica 10.3, but there is no enough information (documented) on how to do that.
I am able to login in LinkedIn and see my user data with:

lk = ServiceConnect["LinkedIn"]     (* works fine *)
ud=ServiceExecute[lk, "UserData"]; (* works fine *)

ServiceExecute[lk, "GroupNames", "Count" -> "3"] (* Nothing happens ...*)

What are the commands to send a simple message to a specific connection of mine?