[BKarner]

Код:

GetPlayerName(playerid, string, 21);
    format(string, sizeof(string), "You have successfully slapped %s! || %s", string, reason);
    SendClientMessage(playerid, 0xF69521AA, string);
    return 1;

Here, you are getting the name of the person who DID /slap.

Код:

GetPlayerName(id, string, 21);
    format(string, sizeof(string), "You have successfully slapped %s! || %s", string, reason);
    SendClientMessage(playerid, 0xF69521AA, string);
    return 1;

This is what you need to change it to.