If you mean that the user selects the location in the application and this needs to be displayed on the map have a look at the geocoding done in this module: https://appstore.home.mendix.com/link/app/29470/Freelance/Function-library-for-geolocation
Or if it’s a mobile app use this: https://appstore.home.mendix.com/link/app/2404/ITvisors/GeolocationWidget
The with the maps widget displaying the location is easy and described in the documentation of the widget
you can use java script action called (GetCurrentLocation) exist into NanoflowCommons module