Hey @Neepee19
Thanks for reaching out here in the Community!
You can use AirPlay to mirror exactly what you see on your Apple device to your Roku TV. However, one requirement for AirPlay to work is that both the Roku and the iPhone need to be connected to the same wireless network. Perhaps you can use a separate device that will serve as a hotspot for the Apple and Roku TV to connect to.
For more information, you can check our Support article here: How do I use AirPlay and HomeKit with my Roku® streaming device?
I hope this helps.
All the best,
Kariza
Kariza D.
Roku Forum Moderator