استبدال المتغير في جمل الاستعلام SQL في Laravel

لدي الكونترولر التالي في Laravel وهنا جزء من التعليمات البرمجية الخاصة بي لاستعلام SQL الذي قمت بإنشائه:

$query = <<<SQL
        SELECT day, date, product1_shift1, product1_shift2, product1_shift3, 
        COALESCE(product1_shift1, 0) + COALESCE(product1_shift2, 0) + COALESCE(product1_shift3, 0) AS total_product1_qty
        FROM (
            SELECT DAYNAME(date) AS day, DATE_FORMAT(date, "%d-%m-%Y") AS date,
                (SELECT SUM(qty) AS product1_shift1
                FROM bill_details 
                JOIN bills ON bills.bill_id=bill_details.bill_id
                WHERE bills.shift_id='48c73e3d-57de-4fea-aae4-7222d7e6afed'
                AND bills.date=bills_master.date
                AND bills_master.customer_id=bills.customer_id
                AND bill_details.product_id='3516c43b-ffe3-4e90-9d93-924a9865c9cd') AS product1_shift1,
                (SELECT SUM(qty) AS product1_shift2
                FROM bill_details 
                JOIN bills ON bills.bill_id=bill_details.bill_id
                WHERE bills.shift_id='463ec995-cfad-46ff-8e65-3115e6e651c5'
                AND bills.date=bills_master.date
                AND bills_master.customer_id=bills.customer_id
                AND bill_details.product_id='3516c43b-ffe3-4e90-9d93-924a9865c9cd') AS product1_shift2,
                (SELECT SUM(qty) AS product1_shift3
                FROM bill_details 
                JOIN bills ON bills.bill_id=bill_details.bill_id
                WHERE bills.shift_id='0a792c5f-84a6-4534-818c-427cfe8cd3ca'
                AND bills.date=bills_master.date
                AND bills_master.customer_id=bills.customer_id
                AND bill_details.product_id='3516c43b-ffe3-4e90-9d93-924a9865c9cd') AS product1_shift3
            FROM bills bills_master
            WHERE bills_master.date BETWEEN '2023-04-07' AND '2023-04-09'
                AND bills_master.customer_id='d9916741-ca61-4a57-b281-15c80fad833c'
            GROUP BY bills_master.date
        ) subquery_alias
        SQL;
        dd(DB::select($query));

ماذا أفعل إذا أردت استبدال متغير PHP ، على سبيل المثال

WHERE bills.shift_id='$phpVariable'?