The following are common causes of the app not working correctly.
A paid plan subscription is required to use the app. Even for development stores, a paid test plan is required.
Enable the app embed in the Shopify theme editor and complete the initial setup.
Check the status on the selling period rules screen and change from "Disabled" to "Enabled."
You need to check in the live environment. Preview does not auto-refresh after settings are changed.
Link the product to the relevant selling period rule.
In Shopify Admin, go to Settings > General > Timezone and select the correct region. After changing the timezone, you will need to update the date/time in existing rules.
Caching may cause a delay in reflecting changes. Wait a moment and check again.
Add inventory or check "Continue selling when out of stock."
Avoid managing checkout rules directly in Shopify Admin. Manage selling period rules within the app screen.
If the issue persists after trying the above, please contact customer support.