Create a product only for your Oliver POS by hiding it in your WooCommerce Web Shop. Here's how to do it.
Yes, you absolutely can! If you want products to be sold in your store only and not online you can hide it in your online shop by going to the products section in your WooCommerce dashboard. Next click on the product you want to hide. Go to the "publish" section on the left-hand-side and click "edit" in "catalog visibility". Here you can customize your product's web shop visibility. Simply select "hidden" to hide the product on your web shop. This way, the product will only be visible on Oliver POS.
The Image below shows where (marked in the red box) in your WooCommerce can a user change product visibility.