If your Puma had come with a factory fitted reverse camera, the camer would be where the boot release or reverse lights are. You can get aftermarket cameras that replace the original boot release say. You can also get a Sync 3 adaptor, so it shows on your infotainment screen as if one was fitted as standard at the factory.
You can also get (as Halfords) an aftermarket kit, that is cheaper. The problem with this type of kit is, it won’t look factory fitted. You will have another display like a SatNav to mount somewhere to act as a reversing camera or there is the option of a replacement rearview mirror, which also act as a reversing camera. Some of these systems have big bulky camera that need to be bolted on the rear of the car, whilst others take a similar approach to above and a replacement boot release handle houses the camera. These can often be found on the likes of ebay and have s so quality.
The fully intergrated one is much better but at £380+VAT is expensive however, you would be eligible for VAT relief, so you wouldn’t have to pay the VAT, as long as the guy Ford is putting you intouch with is both reputable and VAT registered, there wouldn’t be a problem. It maybe worth looking up auto electricians near you and getting a price (VAT free) or if a family member can fit one as its not that difficult and Puma forums will have diagrams of installs 🙂