go to the collection page. Click on "Catalog" or any collection page you want to add to. If there's an existing app, remove it first. Click on "Add a Section," then select "Collections" under apps.

You can change the orientation and location of the collection, style, different video cards. The same customization features apply, like secondary theme color, font change, and size percentage. Save the changes and preview them.

After customizing as per your needs, save the theme, to ensure your changes are not lost.