The app automatically replaces the add to cart/ buy now button with a pre-order button under certain conditions.
If you have both add to cart and buy now buttons on your page, it will replace the buy now button as well in some conditions.
The app works on the following pages:
product page
collection page
home page
on the product quick view
Note: The app is compatible with all the Shopify themes. But if you have any trouble setting up the pre-order button, feel free to reach out to us for support.