1. Verify that your service API endpoint is accessible publicly. You can check this by opening https://2fa.example.com/api/health in your mobile device. It should pass SSL validation and return http status 200 OK. This API provides service discovery and onboarding service. 

  2. If using QR code, try onboarding manually, by entering your authentication service FQDN (https://2fa.example.com) in service domains and tapping corresponding service in services tab in the app.