[Konstantinos]

Any code out of callbacks is invalid. You already got the command /help so a double one is really pointless. It's also pointless to check if the playerid is connected player because if the player was not, then the callback would not even get called.

pawn Код:

public OnPlayerCommandText(playerid, cmdtext[])
{
    if(!strcmp(cmdtext, "/help", true))
    {
        SendClientMessage(playerid, 0xFFFFFFFF, "To be updated.");
        return 1;
    }
    return 0;
}