Programming language used to interact with SQL Server databases
The language for this forum is English. My tiny knowledge of Polish is not enough to understand what you are doing, but I get the impression that you are trying to add the login sa to the server role serveradmin. You cannot do that, and there is no point with it. Since sa is member of sysadmin it already has all permissions implied by serveradmin.
If that does not answer your question, please clarify your question. Preferably in English.