Please Note:
This article is for merchants who HAVE migrated their store's post-purchase pages to Checkout Extensibility.
To enable Replenish on your Checkout Extensibility post-purchase pages, you will need to add the Reminder Widget app block to your Thank You and Order Status pages via the Shopify Checkout Editor.
Adding the app block
Head to the Checkout Editor within your Shopify Store by navigating to:
Shopify Admin > Settings > Checkout
and within the Configurations section, select the Customize button:
At the top of the Checkout Editor, start by selecting the Thank You page from the dropdown:
At the bottom of the Order details section in the left-hand pane of the Checkout Editor, select Add app block:
From the pop-up window, select the Reminder Widget app block from the Replenish section:
The app block will be added to your Thank you page:
Click on the back arrow to return to the editor:
Within the left-hand pane of the editor, you can re-order the app blocks as required by hovering over them and dragging and dropping them into place:
Make sure that you save the page before repeating the steps above for your Order Status page.
That's it!