controller

 public function store(Request $req){

        $me = auth()->user();
        $today = Carbon::now()->format('d');
        $countOffer = Offer::whereMonth('created_at',Carbon::now()->format('m'))->count();
        $offernumber = \Functions::generateOfferNumber($countOffer);
        $spancopsetting = unserialize($this->settings::get('spancop_items'));
        $activity = Activity::where('customer_id',$req['customer_id'])
        ->whereDay('created_at',$today)
        ->first();
        // $spancopActivity=$activity->category!=null ? unserialize($activity->category) : [];

        $offer = Offer::create([
            'offer_number'=>$offernumber,
            'sales_id'=>$me->id,
            'customer_id'=>$req['customer_id'],
        ]);
        $dataproduct=[];
        foreach($req['product'] as $key=>$val){
            $dataproduct[$val]=[
                'quantity'=>$req['quantity'][$key],
                'discount'=>$req['discount'][$key]
            ];
        }

        $offer->products()->sync($dataproduct);


        return redirect()->route('users.show',$req['customer_id']);
    }