Go to Clients, then Attendance
Click the "edit" icon beside an existing delivery route.
Add and remove clients until you have completed your delivery route.
Click on the "Open In Google Maps" button.
This will open up a new tab with the client addresses in a list in Google Maps.
The list will start and end with the address of the organization the user is logged into (with the list of client addresses in between), but can be edited.
If Google doesn't recognize an address, it will not draw the route until that address is removed from the list. This can be done in Google when viewing the list of addresses.
See How Do I Open My Delivery Route in Google Maps? to make sure the route the driver is using is the most optimal.