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Alternatively (especially if you use your BigCommerce at the moment) go through these steps directly before the go-live of your Styla Frontend.
On a different domain, checkout as an iframe:
To make the checkout work on a different domain (as long as your end users have enabled 3rd party cookies in their browsers, which is the default in Chrome, but not in Safari), you should be able to set up the iframe working for the external domain as well.
Log into the BigCommerce admin panel and go to Store Setup > Store Settings.
On this page under Storefront you will find the X-Frame-Options header which needs to be activated. Set to Allow from url and set its value to the domain your Styla Frontend will run on, so
https://mydomain.com.
BigCommerce fields triggering Styla updates
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