On the Qingxupu map, find the entrance to the dungeon, clear out the enemies at the door, and then get the first treasure box.
According to the mission guide, follow the map to the bottom of the waterfall, find the stone, and click the "Go to Another Level" button on the stone to enter the map of another level.
The final decision is a difficult problem in the Genshin Impact game, but as long as you follow the above steps, you can solve it smoothly. Hope this information is helpful to you.