If the product card badge does not appear, check the following in order.
Even if "Show a badge on the product card" is enabled in the selling period rule, the badge is not shown when badge text is empty. Check the text on the before, during, and after cards of the target rule.
Enabling badges in Settings is not enough. On the matching card of the target rule, check that "Show a badge on the product card" is enabled.
In Settings → Product card badge, check that "Show product card badges" is enabled.
Showing product card badges on the online store requires a paid plan. You can save the settings on the free plan, but they are not shown on the online store.
For pricing, see About pricing plans.
Check that a selling period rule is applied to the product.
In the theme editor, under App embeds, check that "RuffRuff Selling Periods" is enabled.
If the default selectors cannot find the product card, specify CSS selectors in Settings → Product card badge → Advanced settings.
For how to specify them, see Customize product card badge design.
If the above still does not solve the issue, contact us through the contact form.
When you contact us, include the following information.
The store's myshopify.com domain
The theme name
The product name or collection URL
The items you have already checked