Garmin Mobile XT CE for WINCE devices 800x480 (City 2016 Indash, Civic 2012, Toyota GLI >2016) Full navigation , with pakistan maps

AoA, I have a Honda audio navigation head unit bought from UK. It is Garmin based and has updated maps of complete Europe. I want to use it here in Pakistan, therefore please guide me how can I load Garmin compatible maps through external USB. The unit is pulled from a 2017 vehicle and comes with 5 years free EU map updates.

Thanks for a detailed reply. At the moment it is displaying base map of pakistan , showing various boundaries and different colour shades but no roads and streets.
The procedure for updating maps is through a USB that reads unique code from the navigation unit and than it needs to be inserted into pc where the Garmin software based on the code gives option to update full set of EU maps. That code written by the unit on USB seems to decide what maps need to be updated.
I am attaching the main sticker and Garmin sticker pasted on the Honda audio-navi unit.

20200102_130327.jpg4032x1960 1.92 MB

20200106_213009.jpg2161x1960 1.83 MB

I will try and extract the firmware no through diagnostic menu. Maybe that is helpful.