Updating Product Items in a Cart Collection

I listed items on a products collection. Added a button on the list. When click on the button, the item is added to another cart collection.
But couldn`t find a way to update the number of items on cart collection.

Buttons do have actions to create collection, but don`t have or very limited actions to update or delete items in the same collection.

I checked the Odering template for a solution. But they also used only create collection action. When you click on couple of times, you add the same product couple of times to the cart, and you see list of same products in the cart. Not the product and the amount of the product in a single line.

Hope I could make it clear, and find a solution:)

You’ll need to have an Order Items collection that relates to both an order and a product. You can then have a screen that has a list of the products and a count of the number of related order items for that product for the current order.

@Ben thank you.
Here is what I am getting.
https://streamable.com/ecm4dc

It looks like you need to change the relationship between order items and products and order. An order item can only have one order and only one product.

I did exactly the same. It does not even show delete option for Order Item for button actions. Am I missing something?
https://streamable.com/912hpv

You need to create the order record before you get to the product list screen. That was the product list screen will have access to Current Order.

Order is created when selecting Store. New Order Item is created on the product list but still no option to delete.

Here is my temporary solution. It creates lots of rows but it works for now:)

This seems like a basic function. But even I am facing a tuff time updating/deleting quantity. @Ben Anything clonable?

@brkn any final solution? your videos are not accessible anymore