What do I need to add Afterpay to my Shopify Store?
Afterpay is available for Shopify merchants with a store address in these countries:
Afterpay US and Cash App Pay are only available in the USA.
The store address must correspond to the Afterpay account region.
Do the following:
Go to Shopify Admin > Settings > General.
Under Store Address, the Country must be one of the following:

The store currency must correspond to the Afterpay account region.
To set the store currency:
Go to: Shopify Admin > Settings > General.
Under Standards and formats, the Currency must be one of these:

Check if you have Automatically at checkout or Automatically when order is fulfilled enabled.

In the Payment Settings, you can also apply manual capture for all payment types. If you have enabled Manually, follow these instructions: