Open DDT on the computer and open the file map_path.ini. By default, it is \SDMMC\MXNavi, change it to \SDMMC\RtNavi path.
After the change, this property is set to read-only.
This is because you have American navigation software in your card. If it still doesn't work, please ask Geka to try again. )
This SDMMC is the name of the card. It is also possible that your card name is StorageCard.
I just changed the directory to DDT. In the map_path.ini file, I am: \StorageCard\DDT.
Not bad.