Usually, the Add to cart button on Quick View is separate from your themes cart. To integrate with your cart, you need to find the Jquery selector of your cart and paste in Quick View > Settings menu > Custom CSS settings tab > jQuery Selector input field. Then it will be possible to update the shopping cart counter of your theme when customers click on the "Add to cart" button on Quick view popup.
Step-1: If do you want to update shopping cart count numbers.
You've successfully copied the CSS selector.