In order to move an agent along the given route, you need to create a Route Provider by code and set it as route provider for the agent.
The code sample can be found in the following example model: https://www.dropbox.com/s/o5w2bw6cn9l8ez8/DynamicRoutes.alp?dl=0
You can specify any route drawn on the GIS map as argument of the function "getCustomRouteProvider()".
One important comment to the example model: when the initial location or target for an agent is defined as GIS Point of a network, the agent uses the shortest (fastest) route of the network to reach the destination.
In order the agent follows the route specified while creating the custom route provider instead of, the agent is initially placed in the point defined by the latitude and longitude of the "gisPointStart" and moved to the point with coordinates (gisPointEnd.getLatitude(), gisPointEnd.getLongitude()).