Welcome to the Roku Community, @Justinmarois!
Thanks for letting us know about this issue you had. To use casting, the supported app must be installed on your mobile device and Roku TV. You must also connect your phone or tablet to the same wireless network as your Roku device. You can do this wirelessly with supported apps like YouTube and Netflix by opening the casting icon on your phone or tablet and selecting your Roku device.
If you encounter errors accessing it, please follow this support article: Cast from a mobile app to your TV.
We hope this helps. Please keep us posted if the problem persists.
Best,
The Roku Community Team
John
Roku Community Moderator
