Hi anitra199,
First, make sure you are following the guidance outlined in Add a smart home accessory to the Home app for the best results. This includes updating your iPhone, if applicable; and confirming your Roku TV is compatible and the firmware is up-to-date.
We also did some research on the Roku Support website, and they have an in depth troubleshooting page for connecting your Roku TV with HomeKit. We encourage you to review this page to confirm your Roku TV and the software version are compatible, your settings are correct, and then reach out to Roku Support directly if you need further assistance. They will be the experts when it comes to their products.
How to use AirPlay and HomeKit with your Roku® streaming device
Are there any settings to check before using AirPlay and HomeKit with my Roku device?
If you have a Roku TV or Roku Streambar it may not stay connected to your wireless network when powered off. To maintain the network connection and allow AirPlay and HomeKit to connect to your Roku device when powered off, use the steps below to turn on a feature called "Fast TV start" (on your TV) or "Fast start" (on your Streambar).
1. Press Home
on your Roku remote
2. Scroll and select Settings
3. Select System
4. Select Power
5. Select Fast TV start (Roku TV) or Fast start (Streambar)
6. Highlight Enable 'Fast TV Start' (Roku TV) or Turn on 'Fast start' (Streambar) and check the box
* Note:
* Fast TV start and Fast start use more power than normal standby and override default power settings.
* Roku players remain powered on and connected to your wireless network.
Kindest Regards.