If customers see Add to cart instead of Book Now (or your customized button label), or the booking calendar doesn't open, work through these checks in order — one of them almost always fixes it.
1. Turn on the app embed in your theme
The button only appears when the SMS Reminder Booking app embed is enabled on your theme. In your Shopify admin, go to Online Store → Themes → Customize → App embeds, switch on SMS Reminder Booking, and Save. This is the most common cause.
2. Make sure the product is linked to an appointment type
Only products linked to an appointment type swap to Book Now. If this product still shows Add to cart, link it first (see Link a product to an appointment type).
3. Check the product is published
The product must be active and available in the Online Store sales channel. A draft or unpublished product won't show the button.
4. Refresh and clear cache
After any change, Save, then reload your storefront with a hard refresh (Cmd/Ctrl + Shift + R) or open it in a private/incognito window — themes and browsers cache the old version.
5. Older ("vintage") themes
Some older themes can't display the embedded button at all. In that case, use your booking-page link instead — add it to the page, your menu, or a button. Customers book the same way.
Just switched themes?
If you used to see Book Now and now see Add to cart, your new theme needs the app embed switched on again (step 1) — theme settings don't carry over.
Still not showing? Start a chat with us using the Messenger in the bottom-right corner and let us know your store URL and the product page, and we'll take a look.