Hi @Cherry252 , there's no compatible cameras available for this discontinued product. You probably can find a replacement BT 1030 on popular online 2nd hand / auction websites.
Or try Discomm who's BT's partner for refurbished products. Even if the product doesn't appear on their website, give them a call as sometimes they have spares.
Also, if you're looking for the camera only and re-use the screen you already have, you should first check that it is possible to add a camera to the screen. Sometimes these are pre-paired in the factory and don't offer the option to add a new camera. Check the menus for an "add camera" option (or similar) and the user guide.