I want to publish to Youtube directly from photopia and the system answer is always (in french !)
"Impossible de vous connecter ce navigateur ou cette application ne sont peut être pas sécurisés"
I use Chrome from Google and I have already an account which works for others applications!
We're aware of this issue and it is near the top of our priority list, although it has not yet been resolved. There are a number of complications here that have slowed things down, but we're on it.
For now, you can output your shows through "Publish" > "Video File" using the "MPEG-4" option. I recommend the "1080p (Full HD)" preset. Save the resulting video to you hard drive then upload that MP4 to YouTube through your browser. This workaround should provide the same high quality video as the direct YouTube output option, albeit with a few extra steps.