Why can't SPO be opened in Safari?

At the end of March 2020, Apple has rolled out a new change. All cookies used by 3rd party are disabled. Since our app is an embedded app inside Shopify Portal, our cookies are blocked by Safari. Therefore, you'll see a blank page. 

We don't have a fix here unless we removed all cookies. You can switch to Chrome. Alternatively, you can use Safari to visit our AppStore listing. Click 'Add app' button. Then you can enter our app. But some functions may be affected.