Car without HU, no registration to the next workshop?

Hello, unfortunately, I had to get a car because of my job. the car was standing at a friend’s place and was there also Klomplett rep. well, since there is a private workshop I have to drive the car for the HU about 20km further to the next place. to shorten the whole ^^ tag marks there is no longer for cars without HU. a well-known thought you can move the car if it is insured until the next workshop/TÜV. is that true? the car has no HU, is not registered, h at no signs, nothing. the only thing I can do to register with the insurance company (liability) can hardly imagine this without marking through the against. unfortunately I didn’t really find what was in the net in this respect. therefore I would be happy if someone could give me an exact answer. lg felix