This included the Roku 3,
Roku 4 or Roku Ultra.

Open up the settings menu on your Roku TV.
Navigate to Screen mirroring (beta), then toggle the checkmark to ‘enable screen mirroring’.step by step Install Kodi on Roku hacks
Select between ‘prompt’ and always allow’. The always allow module is recommended for jailbreaking your Roku TV.
step by step install kodu on roku 2
Download Kodi on a mobile phone, laptop, or Tablet.
Open up your settings on your device and navigate to display > wireless display> then select your Roku TV device.
Tap ‘accept connection’ on your Roku TV.
Launch Kodi on your secondary device (Phone, laptop, tablet)
Congratulations, you will now have a Jailbroken Roku TV.