On the Expeditions page, you can either assign each order separately to a courier, or select multiple orders and mass assign them.
To generate a rollcart (see What is a rollcart? section for details), select the orders for the desired courier and click on the “Add rollcart” link on the bottom of the page.
Once the rollcart is created, you can print it and have the courier use it to track his deliveries. You can also collect delivery signatures on it if you wish – or use the printed expeditions for that.
The rollcart can also be used to calculate the optimal route for a courier’s deliveries. Pick a start position, and optionally an end position, and click “Optimize route”. This will reorder the expeditions to create the shortest route to all of them. This is the same order the courier will see them in his mobile app. Click “See route” to see a map of the route – note that only route order is optimized on this map, in practice the courier still needs to use something like Google Maps to navigate between stops.