Hello Yani48,
Thank you for reaching out to Apple Support Communities, and we'll be happy to help in any way we can. We understand you're having issues with accessories in HomeKit. Check the following steps to make sure all is set correctly to resolve the issue:
1. Check that you turned on Bluetooth on your iOS device.
2. Check that you're connected to Internet over Wi-Fi.
3. Power cycle the device by unplugging it and plugging it back in.
4. On iOS 10.3 or later, go to Settings > [your name] > iCloud and turn on Home and iCloud Keychain. On macOS, make sure that Home and Keychain are turned on in System Preferences > iCloud.
5. Download the manufacturer app* for each accessory, then check for updates. If an update is available, check that the accessory is on and keep it nearby until the update finishes.
You can add accessories only from an iOS or iPadOS device.
6 Check the accessory manual for extra hardware requirements. If extra parts are required, you need to buy the hardware, get the manufacturer app, and set up through that app.
7. Turn off every iOS device or Mac that you use with the Home app. Then turn them back on.
We hope this helps.
Cheers!