Mounting for bicycle rear light @ luggage rack

Because my e-bike is currently being repaired and this process will take some time, I have to equip my good old *motorless* bike with lighting.
The battery-operated lamps should be easy to install and remove. The front lamp came from factory with a quick release lock. However, there is no good place to mount the rear lamp for quick-out.

Therefore I designed this adapter to attach the rear lamp to the luggage rack.