You could try Airplay Mirroring which may work if the app/website is only allowing Airplay of audio output.
How to AirPlay content from your iPhone, iPad, or iPod touch - Apple Support
You could try Airplay Mirroring which may work if the app/website is only allowing Airplay of audio output.
How to AirPlay content from your iPhone, iPad, or iPod touch - Apple Support
Apps and websites can control if video or only audio or neither can be displayed.
It may be an issue with the content provider settings.
video not streaming via airplay only sound