When out of stock...

Greetings to all.
I have been looking for a plugin or a modification that could manage, as an example image, the stock of products when an item runs out, but without success.
I believe I am not the only one who encounters problems when an item is no longer restocked or temporarily ends and the native stock management of zencart is not able to help in these situations.
Does anyone know of a function like this or how it is possible to implement it?

https://docs.zen-cart.com/user/admin_pages/configuration/configuration_stock/ has a listing of all the Configuration settings for stock.

I think OP is looking for item by item out of stock handling configuration though, which Zen Cart does not have.
It has the global settings which @dbltoe linked above.

@swguy , @dbltoe
Exactly: global settings are fine, but for correct management it would be appropriate to insert these individual variants directly into the product sheet.
Practical example to avoid misunderstandings:
Checkout enabled for out of stock products (which I can restock from the supplier)
Checkout disabled only for products that I have indicated as "last pieces" and that become unpurchasable when the quota reaches zero.
Is it possible that no one is interested in helping me develop a plugin that allows this function?

POSM plugin has more comprehensive Out of Stock messages...which could/should really be extended to allow the same options for non POSM-managed products.
I built on that first and also modified product_info to cover all the potential out of stock scenarios.

Your work on the POSM is already a big step forward for the Zencart structure; to have a quick solution to my request it would be enough to implement a "do not allow checkout" in case of out of stock. However, in my opinion the best solution would be to insert this function directly into the core, also because it is foreseeable that not all products have options and the management directly from the product sheet would be of unique convenience.