Hi
It goes without saying that you should be able to add a second audio track to your project. However it may not be readily visible due to the sizing of the Track/preview area....
Here the preview is large at the expense of the track height........
But in fact, a second audio track is actually present. If the circled white lines are are dragged upwards, the Video and Audio tracks are made wider at the expense of the preview area with correct adjustment Audio track 2 will come into view....
However with multiple tracks their height will only grow to a small extent.
If the "Drag and Drop" prompted area is visible the track you add should be visible at the outset.
Nat