My upload button doesn't appear on the Turbo theme
If you're using the Turbo theme and your upload button doesn't appear, or only shows up after refreshing the page, you almost certainly have an issue with your theme settings.
The Turbo theme has a performance mode called 'Ludicrous'. It doesn't actually seem to offer real-world speedup, but it does break large numbers of apps including UploadKit. It's also been responsible for a number of Javascript errors we've seen on customers' stores.
We strongly recommend editing theme settings and changing the 'Performance' setting to 'Sport' (and not 'Ludicrous'). It won't slow your site down, but it will make your third party apps work correctly - and perhaps even resolve other issues your customers have been having with your theme.