Select the products that you wish to enable the Pre-Order functionality:

Click on ON at the Pre-Order field (selecting OFF will bulk disable the Pre-Order):

This will enable Pre-Order for all the selected products.

If you wish to enable Pre-Order for ALL products, tick on Select All checkbox.

and proceed to select the Select all <NUMBER>+ items from your store button to select the products for the whole store. If you have a huge store with thousands of items, it will take 20 to 50 seconds for it to load:

Select the ON button to enable this process:

A pop-up notification notifying you the total number of products/variants that will be affected will be shown and you are required to confirm this process by selecting Enable Pre-order button.

A progress bar will then show the progress of this process:

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