As you can see the app shows me what chord should I fingerpick: Bm.
To do so I hold bare with my first finger on the 1 fret and my third finger on the 4th fret of the G String.
So Im' simply holding Bm chord as for strumming.
But as you can see on the screenshot, yousician shows that I should play everything with the first finger. Can someone explain me why is it happening and how I'm supposed to play it.