Hi @BTNC,
Welcome to the Roku Community!
If your Fire TV Stick isn't detected on your Roku TV, ensure it is securely plugged into an HDMI port, that you've selected the correct input source on your Roku TV remote, and that both devices are powered on and connected to a stable Wi-Fi network.
We hope that's helpful. Please keep us posted on what you find out.
Best,
The Roku Community Team
John
Roku Community Moderator