Stock management

We have added custom fields to the product page for adding the children in the summer camp,
Issue we are facing is: We have stock on product for assume 100.
Once the booking is made of three children by using the PPOM fields its only reducing the 1 stock quantity from the stock, where it has to reduce the 3 .

Note: we have seen the option of stock management fields in the backend, but it is coming with field based. we need an option to manage the stock with Product based on the fields we need to count the quantity.

Let us know, if its possible in the pro plugin. If yes we would like to purchase.

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