To start plotting your route, tap the screen to drop your first pin, that will be your starting point. Then you can drop another pin to indicate your finishing point. If you want to go via specific locations or avoid certain areas you can drop multiple pins as waypoints, with the last pin your drop being your finishing point.
If you decide on of your pins is in the wrong place, you can "touch and hold" the pin and then drag it to the new location. A bit like this:
If you have any further questions please feel free to contact our team.