How to display cart items in a modal window in bootstrap 4 using js?

Question

JavaScript

Good afternoon, could you please tell me how to quickly implement such a task?
What day I fight

When adding products, a list is displayed on the page itself, after clicking on the "Place an order" button
And in the modal window these products are no longer displayed

https://codepen.io/Zhelezniy/pen/QWNedQE

How to make it so that in modal window they were?

for example, opened a modal window with a product, clicked add to cart.
then opened the shopping cart in the modal window, and here is the whole list of products

Answer 1

The question is not very clear.
But, if I understand correctly, you want that when adding a product to the cart, it appears immediately in one block, and simultaneously in another block, inside the modal window. So?
If so, then I see 2 solutions, perhaps there is a dependence on what / how goods are added to the initial block.
Option 1 - respond to the button click event - change js to add the product immediately and to another block, which is inside the modal.
Option 2 - use MutationObserver - monitor the state of the original block. When it changes - read and change the second block inside the modal.