We have a simple solution that just about anyone with basic mechanical skills can install. It comes with a factory GM camera, extension cable, and a small fully adjustable bracket assembly that allows you to attach the camera onto the third brake light of your topper. Check it out here:
https://www.camerasource.com/factory-digital-mirror-camera-relocation-housing-kit-for-2019-2023-gm-trucks
We have a universal style kit that can be mounted on any flat surface, i.e. doesn't require a third brake light for mounting. This model will be great for people with drop in campers etc. https://www.camerasource.com/factory-digital-mirror-camera-universal-relocation-kit-for-2019-23-gm-trucks-camera-included?q=cs-3gm
If you have questions please call 888-844-9763 as we do not frequently monitor private messages on this forum!