Intending to turn left at this junction, have you assumed the proper traffic lane?

In the video, you are driving along a street where the tram tracks run in the left lane of the roadway, and before the junction you move into this lane, driving on the tracks. Since you intend to turn left, this is the proper lane: before a left turn you move towards the centre of the roadway. The answer is: yes.

The Road Traffic Act requires a driver who intends to turn left to move towards the centre of the roadway, and on a one-way roadway towards its left-hand edge. The left lane with the tracks is exactly the lane closest to the centre. When driving on the tracks, you must make way for an approaching tram, and at a junction the tram has right of way regardless of its direction, and when turning left you also give way to oncoming vehicles going straight on or turning right.

Legal basis: Art. 22 para. 2 point 2, Art. 16 para. 6 and Art. 25 para. 1 and 2 of the Road Traffic Act (Prawo o ruchu drogowym)