I assume you are in Europe since all North American e-Golf cars had the backup camera included.
Personally, I would try to go for retrofitting the factory backup camera that's integrated into the rear logo/hatch release. However, I have no idea how much parts would cost or whether some kind of coding would be required. I'm assuming that the wiring is present.
2015 e-Golf LE (returned) | 2018 Tesla Model 3 LR | 2012 RAV4 EV Shoreline w/JdeMO | Leviton EVB40 & Jesla Home Charging | 4.32kW Motech/Enphase PV + 2x Powerwall 2 AC