This app uses an app embed block to enable the display of the preorder button and other elements.
The app embed block must be activated on your store. To activate it:
In your Shopify admin, go to Online Store > Themes.
Find the theme you want to edit and click Customize.
Click Theme settings.
Go to the App embeds tab.
Find Magical Preorder and click the toggle to turn it on.
Watch this short video walkthrough of the activation process: