Pre-requisites:
If you have auto collections, then go into those collections and make a ruleset to prevent them from auto adding to the product type "hidden" which you created in the previous steps.
Once you confirm there are no collections associated to the product, you will need to add some custom Metafields. Once you have a Metafield app installed you can go back to your product and continue on.
Once the Metafields are configured, you can go back to your product and set it active.
And... you're done! You can now return this product to a Rebuy widget via the attached Data Source, it can be added to the cart and purchased, all the while users will not be able to find this product on your online store!
Note: For the ReCharge checkout you can even go a step further and make the product unavailable for sale on all sales channels and it will still be purchasable via the ReCharge checkout. If that’s the only place you’re going to surface it, you can actually skip pretty much all of the steps in this guide and just mark it as unavailable for sale on all sales channels and then surface it only via your rebuy widget embedded in the ReCharge checkout.
METAFIELDS GURU ISN'T HIDING THE PRODUCT?
If the product page of the gift is not concealed, this guide will demonstrate a workaround by eliminating the Add to Cart Button from the gift's product page.