https://www.adfc.de/artikel/den-regeln-der-stvo-folgen

In principle, cyclists may choose whether to turn left directly or indirectly.

When turning directly left, cyclists may also leave cycle paths that are subject to mandatory use in order to turn directly left, but must pay attention to straight ahead traffic, which has the right of way. If you want to turn directly left, get into the middle of the lane in good time and follow the traffic lights of the corresponding lane.

When turning indirectly left, the cyclist first stays to the right and crosses the junction or intersection. They then turn left. The cyclist therefore crosses two lanes straight ahead.

Of course, the question arises as to whether you want to cycle on the road or prefer to stay on the cycle path.