[Mean]

You can use IsPlayerAdmin.

pawn Код:

//Example
CMD:loltest(playerid, params[]) {
    if(!IsPlayerAdmin(playerid)) return 0; // If the player isn't logged into RCON, it will return "Unknown Command" and stop the code from executing. If the player is logged into RCON, the code after this line will get executed. That's what this line does. 
    SendClientMessage(playerid, -1, "Lol you're an admin");
    return 1;
}