From your Shopify admin, go to Online Store -> Themes.
Find the theme that you want to edit, and then click Customize.
In the Popup group -> Add section -> choose Promotion Popup
Inside the Promotion Popup group, you can add groups and a wide variety of other blocks as needed.
This allows you to flexibly customize the popup layout and content based on your requirements.
Note: You can adjust the popup display timing in this section.
