Framer & Customers accounts who want to add framing capabilities to WooCommerce or Shopify have access to what we call the "Connect Page". When connected to a third party cart system, anybody who designs on the connect page will be redirected to that third party cart for checkout. Your connect page URL can be found under Menu -> Settings -> Third Party Cart Connection.
Note
Although the connect page is available and can be used for third party integration, you may also allow customers to access your framing studio and place orders for review.