You can access and edit your device list here.
Manufacturer: Roku Inc.
Category: pre-selected as 'Connected devices'
Model info can be found when you open your Roku TV Settings > System > About > press the right arrow key
See example image below (example: 3810X - Roku Streaming Stick+)
4. Model Release Date:
Google: Model name + "release date"
5. Operating System: Roku OS
All Roku devices run on Roku OS
6. OS version:
Version info can be found when you open Settings > System > About > press the right arrow key
See example view below (example: 9.2.0 --> please enter this as Roku OS 9.2 on the platform)
7. OS Release Date:
Check this page for your Roku OS version release date.
This is an example how the final device adding screen would look like:
Please note: Your Roku will generally update to the newest OS version automatically at regular intervals, please verify the current OS version before every run.