The issue with your site is it’s SSL.
We do not support SSL out of the box, you would need a custom setup for that, which can get expensive. If you would like a quote on that, please use our Free Quote page.
The cheaper solution is to do some custom development of your own to exclude the customizer pages from SSL. That means they should have URLs that start with https://, not https://. If you switch those pages like /customize/ over, they will work.
Small note, you can see in the address bar where the red X is (in chrome) that the SSL is not valid. This is because things like your logo in your header are linked to https:// URLs. You will also need a valid SSL certificate.
SSL is not necessary for every page in your website, but it is essential for your checkout and payment pages, like /cart/ and /checkout/ etc. You can control whether or not your whole site or just checkout if forced to SSL in your WooCommerce settings.
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