Create either a separate page or modal for Order confirmation
Timeboxing/estimate of this issue: 2-3 days for the new page/modal. Couple of days for interacting with the API, making sure the order gets submitted and stock gets updated. (including any unforeseen issues/edge cases)
Create HTML page for order summary
Utilise the PATCH endpoint within the ProductService - reduce stock level by how many the user buys.
Utilise the POST endpoint within the ProductService