new laststate[MAX_PLAYERS];
new Text3D:reloadlabel[MAX_PLAYERS];

public OnPlayerUpdate(playerid) //Add here
    if(GetPlayerWeaponState(playerid) == WEAPONSTATE_RELOADING && laststate[playerid] != WEAPONSTATE_RELOADING)
    {
        //Player starts reloading
        //Do your label stuff here, e.g.
        reloadlabel[playerid] = Create3DTextLabel("Reloading...", 0xAAAA33FF, 0.0, 0.0, 0.0, 30.0, 0, 1);
        Attach3DTextLabelToPlayer(reloadlabel[playerid], playerid, 0.0, 0.0, 1.0);
    } else if(GetPlayerWeaponState(playerid) != WEAPONSTATE_RELOADING && laststate[playerid] == WEAPONSTATE_RELOADING)
    {
        //Player finishes reloading
        //Delete the label here
        Delete3DTextLabel(reloadlabel[playerid);
    }
    laststate[playerid] = GetPlayerWeaponState(playerid);
    
    return 1;
}