How to Automatically Apply a Discount to a Specific Product When Product X Is Added to the Cart..?

I am using Balbooa Gridbox eCommerce and want to create a conditional pricing or automatic discount rule.

For example:

* If a customer adds **Product X** to the cart,
* Then the price of **Product Y** should automatically become discounted (or even free).

I would like to know:

1. Is this possible directly in Gridbox?
2. Can it be done using custom JavaScript, coupon logic, or a plugin?
3. How can I apply the discount automatically without requiring the customer to enter a coupon code?
4. What is the best method to achieve this while keeping the cart and checkout working properly?

Example scenario:

* If customer adds “Acrylic Sheet” to cart,
* Then “Installation Service” should become free automatically.

Please explain the setup process step by step.