You can specify your geographic location by setting georeferencing in the modem settings, as shown on the screenshot below. The geolocation of the point X=0, Y=0 is specified.
Note that the Y axis should point to the true North for a correct conversion of the coordinates. Rotate the map or the submap to get this direction (see the section "Georeferencing point" of the operating manual for more details):
https://marvelmind.com/pics/marvelmind_navigation_system_manual.pdf

After georeferencing, the system reports the correct latitude and longitude of the mobile beacon via the NMEA0183 or U-blox protocol (select the protocol in the 'Interfaces' section of the settings).