Hi there philipfromcarrickfergus,
Welcome to Apple Support Communities. First, you need to confirm that your camera is compatible with the Home app. The list of compatible accessories can be found here:
Home app - Accessories - Apple
If you camera is listed, follow the steps per the Apple Support article to get connected: Add an accessory to the Home app - Apple Support
Add accessories with your iPhone or iPad
To add an accessory to the Home app, use your iPhone or iPad. You can't add accessories to the Home app on Mac.
1. Open the Home app and tap Add
.
2. Tap Add Accessory
.
3. Use the camera on your iPhone or iPad to scan the eight-digit HomeKit code, or QR code on the accessory or accessory documentation. If you have an iPhone 7 or later and see
on your accessory, hold your iPhone near the accessory to add it.
4. When your accessory appears, tap it. If asked to Add Accessory to Network, tap Allow.
5. Assign your accessory to a room and name it to help you identify it in the Home app and control it with Siri.
6. Tap Continue, then tap Done.
If you run into any trouble, follow the steps:
If you can't add an accessory
• Update your iPhone or iPad to the latest version of iOS or iPadOS.
• Make sure that your accessories support HomeKit, AirPlay 2, or Matter.
• To use and manage your home in the Home app on all of your devices, sign in to iCloud with your Apple ID on every device. Then turn on iCloud Keychain and Home in iCloud Settings.
Now, if your camera is on the list of compatible accessories, you will not be able to add it to the Home app.
Feel free to reach back out if you have any questions.
Good luck!