Select a product and eliminate that option

You can use the Inventory widget as your Product tool instead. 

link: https://widgets.jotform.com/widget/inventory 

You can set quantity available for each product using the inventory widget.

So if you set only 1 Qty for each product, that item/product will only be available on your form once.

Let us know this workaround will not work for you.

Thanks.

Additional:

Another option is to use Unique question feature.

User guide: How-to-set-Form-Limits-Based-on-a-Unique-Question

What it does is, it makes each of the items/options unique. So they will not be selectable more than 1x on the form.

Cheers