Routing is the ability to let the device make a route between two locations using roads and paths. This option is deeply rooted in Garmin devices and now you can also have it in OruxMaps using third-party routing services downloaded on your device (offline).
When you long press a point in the map, you will be presented with a menu. One of the options is "Direct To". Selecting that you have the option "Search route to using...".
By selecting "GraphHopper (offline)". The first time you do that you get the message:
Press "Go Settings" and select "Download Graphhopper Maps". Next press "europe" and then "europe_iceland.ghz". Then press Accept. The download will begin in the background. When done you will get the message "Resource downloaded OK". That should be it.
Next time you ask for directions, you can select the offline version of Graphopper.
NOTE: This routing works well with the POI Search in this blog here: https://www.gpsmap.is/post/offline-poi-search-in-oruxmaps