How do I update my Apple TV HD?

The Apple TV app for the Roku platform has a different versioning

than the system software versioning of the Apple TV box.

If you have the Apple TV box [A1625 or later], then you can update that system software to tvOS 17.4.

Update your Apple TV - Apple Support

If that is not successful, then please detail what happens instead.

If there are no listed outages:

System status - Apple Support

then I would suggest to contact an expert from the Apple Support staff for further assistance. Contact Apple for support and service (phone numbers) or start your support request online (chat/​email/​callback).