To avail the sibling discount:
Add an item for one student to your cart, then select the next item for the next student/sibling. Add both items to the cart.
Navigate to your cart by clicking on the cart icon in your screen's top right corner.
During checkout, enter the sibling discount code provided by the institution into the Discount code box, then click Apply.
The discount amount will be deducted from the booking summary, allowing you to proceed with payment.