You'll open Shopify's checkout editor and add the Zenith survey block to the two pages customers see after they buy: Thank you and Order status. Placing it on both catches customers who skip the confirmation page and come back later to check their order.
In your Shopify admin, click Settings in the bottom-left corner.

Choose Checkout from the left menu, then click Edit next to your active configuration.

This menu is where you switch between the two pages. The numbers show which step happens on each: step 4 on Thank you (under Post purchase), step 6 on Order status (under Customer accounts). Choose Thank you now.

In the Main or Order summary section, click ⊕ Add block, then select Post Purchase Survey.

Click Save in the top-right. The survey is now on your Thank you page.

Open the page selector again, choose Order status under Customer accounts, and repeat steps 4 and 5.
