Multiple cart items in single checkout.

Good day, can someone give me an example of how to implement a cart checkout with multiple items? Like I have 5 items in my cart and I want to check out all the 5 items in a single checkout.

My current code can only check out a single item at a time.

public function checkoutItem(Request $request)
{ 
    $id     = $request->user_id;
    //Status TESTED AND OK.
    try{
        //Check if cart has an item whith status id 1 (Added).
        $cart = \DB::table('cart_items')
                ->whereRaw('cart_items.id = ' .$request->cart_items_id. 
                    ' AND cart_items.product_id = ' .$request->product_id. 
                    ' AND cart_items.status_id = 1')->count();

        if($cart != NULL){

            Stripe::setApiKey( config('services.stripe.secret') );
            $student= \App\User::find($id);

            //Get the product details using the product_id
            $product= \App\Product::find($request->product_id);

            //Check if student's has no stripe id.
            if($student->stripe_id == NULL){
                //create stripe id for student.
                $customer= Customer::create([
                                            'email'    => request('stripeEmail'),
                                            'source'   => request('stripeToken')
                                            ]);
                //Update stripe_id from null to newly created stripe_id generated by stripe.
                $user= \App\User::where('id', $id)
                ->update( array('stripe_id' => $customer->id) ); 

                //Charge the student.
                Charge::create([
                    'customer'      => $customer->id,
                    'description'   => $product->description,
                    'amount'        => ($product->price * 100) * $request->qty, //Should be in cent.
                    'currency'      => 'aud',
                    'receipt_email' => $request->stripeEmail,
                    'metadata'      => array(
                                            "product_id"        => $request->product_id, 
                                            "product_name"      => $product->name,
                                            "product qty"       => $request->qty,
                                            "product_type_id"   => $product->product_type_id,
                                            "sub_type_id"       => $product->service_sub_type_id,
                                            "user_id"           => $id,
                                            "fullname"          => $student->first_name." ".$student->last_name,
                                            "email"             => $request->stripeEmail
                                            )
                    ]);
            //If student's has already stripe id, create a charge.   
            }else{
                //Charge
                Charge::create([
                    'customer'      => $student->stripe_id,
                    'description'   => $product->description,
                    'amount'        => ($product->price * 100) * $request->qty, //Should be in cent.
                    'currency'      => 'aud',
                    'receipt_email' => $student->email,
                    'metadata'      => array(
                                            "product_id"        => $request->product_id, 
                                            "product_name"      => $product->name,
                                            "product qty"       => $request->qty,
                                            "product_type_id"   => $product->product_type_id,
                                            "sub_type_id"       => $product->service_sub_type_id,
                                            "user_id"           => $id,
                                            "fullname"          => $student->first_name." ".$student->last_name,
                                            "email"             => $student->email
                                            )
                    ]); 
            }

            //If successfully charge, status_id wll be updated from 1(Added) to 2(Checkout).
            $upd_cart_items= \DB::table('cart_items')
            ->leftjoin('carts', 'cart_items.cart_id', '=', 'carts.id')
            ->whereRaw('cart_items.id = ' .$request->cart_items_id)
            ->update(['cart_items.quantity' => $request->qty,'cart_items.status_id' => 2, 
                      'cart_items.updated_at' => Carbon::now()->toDateTimeString()]);
        
            return ['success' => true, 'message' => "Product was successfully purchased"];
            
        }
    }catch(\Stripe\Error\Card $e){
        return['error' => $e];
    }
}