Creating unique order

I know it should be simple :(

My problem is, I have an app for libraries and students, so libraries can have many books in their library this is the tables.

  /**
     * Run the migrations.
     */
    public function up(): void
    {
        Schema::create('books', function (Blueprint $table) {
            $table->id();
            $table->string('book_name')->unique()->nullable();
            $table->string('author_name')->nullable();
            $table->string('edition_number')->nullable();
            $table->string('volume_number')->nullable();
            $table->timestamps();
        });
    }

public function up(): void
    {
        Schema::create('libraries', function (Blueprint $table) {
            $table->id();
            $table->string('name')->unique()->nullable();
            $table->string('phone')->unique()->nullable();
            $table->string('CR')->nullable();
            $table->string('district')->nullable();
            $table->string('city')->nullable();
            $table->string('google_maps')->nullable();

            $table->foreignIdFor(User::class, 'user_id')
                ->constrained('users', 'id')
                ->cascadeOnDelete();
            $table->timestamps();
        });
    }

 public function up(): void
    {
        Schema::create('book_library', function (Blueprint $table) {
            $table->id();
            $table->string('qty')->nullable();
            $table->decimal('price', 10, 2)->nullable();
            $table->text('offer')->nullable();

            $table->foreignIdFor(Book::class, 'book_id')
                ->constrained('books', 'id')
                ->cascadeOnDelete();

            $table->foreignIdFor(Library::class, 'library_id')
                ->constrained('libraries', 'id')
                ->cascadeOnDelete();
        });
    }

    public function store(Request $request)
    {
        try {
            DB::transaction(function () use ($request) {
                $order = Order::create([
                    'total_payment' => 0,
                    'user_id' => $request->user()->id
                ]);

                foreach ($request->carts as $cart) {
                    foreach ($cart['books'] as $book) {
                        $order->library_id = $book['library_id'];
                        $order->save();

                        $order->increment('total_payment', $book['price']);

                        $detail = Orderdetail::create([
                            'order_id' => $order->id,
                            'book_library_id' => $cart['book_library_id'],
                            'book_id' => $book['book_id'],
                            'price' => $book['price'],
                            'total_price' => $book['price']
                        ]);
                    }

                    if (!$order->latestStatus(Order::STATUS['sent_to_library']['key'])) {
                        $order->setStatus(Order::STATUS['sent_to_library']['key']);
                    }

                    BookLibrary::findOrFail($detail->book_library_id)->decrement('qty');
                }

                $request->user()->carts()->delete();
            });

            return redirect()->route('user.order.index');
        } catch (\Exception $e) {
            Log::error($e);
        }
    }

what i want, but let's say the Library A have books A,B and Library B have books A,B. When the user order from library A the books A,B it should be in one order even he also at the same time order from Library B the books A,B would be another order. This is what i get when i create orders https://pasteboard.co/GXhllDhyQa6f.png I want to group the order by the library_id

will appropriate your help.