For the initial planning of a mission, you don´t need to be connected to the drone. You will just need the controller.

1. Fig. 1: Choose "Flight route"
2. Fig. 2: Flight route menu
   1. Here you will see all the routes you created before
   2. You can add new missions by clicking the plus in the top right corner
3. Fig. 3: Choose "Create a route"
4. Fig. 4: Zoom in to the area you roughly want to map
5. Fig. 5: Tap the outline corners of the area that you want to map
   1. You can add new corners in between by clicking the small +-Icons on the individual lines
   2. Click the checkmark in the top left corner to save your mapped area

1. Fig. 6: Select "M3E Series" if flying the DJI Mavic 3M
2. Fig. 7: Select "M3M" if flying the DJI Mavic 3M
3. Fig. 8: Select if you want to also take MS images

1. Drone setup

For reference here also an official video by DJI: How To Start A Mapping Mission And Create 2D Maps- Episode 9