Flex provides a Shopify payment app to make it easy to accept HSA/FSA payments in your Shopify store checkout flow.

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Shopify checkout page

When a customer goes to checkout from your Shopify store, they’ll be able to select “Flex | Pay with HSA/FSA” and then be redirected to a hosted Flex Checkout page.

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Hosted Flex checkout page

Upon successful completion, the customer will be redirected back to the Shopify success order page. The order will appear in your Shopify admin just like a regular order.