Thank you for your interest in API v2.
API v2 is more secure than v1 so it applies CORS policy.
You have to add "Access-Control-Allow-Origin: *" HTTP header to your font files. See details in our FAQ
You can see the loading errors in the debug log:
Please check the debuge log. It contains a lot of errors in your HTML.
You can also check our examples project. It has the sample code with a custom font in all supported languages: