In order to manually update the order of stops, follow the steps:
Tap on the ⠇to the left of the route info field. The route options field is available in the list view and the carousel view.
Select “Reorder stops” in the pop up menu.
Drag and drop stops in the order you want them in
Once you are done, tap “Done” to save the new order of stops.
To automatically order your stops in the most optimal way, tap "Optimize Stops" in the route options menu.