To display maps into your Progressive Web App (PWA), you'll need to set an external map service. You can choose between Google Map Platform or Mapbox.
Both platforms give you the possibility to display maps for free on your PWA up to a certain limit.
Once you reach that limit, they both have a pay-as-you-go system of payment:
Mapbox Pricing: https://www.mapbox.com/pricing/
Google Map Pricing: https://cloud.google.com/maps-platform/pricing/sheet/
If you wish to set an account for Mapbox, please follow instructions of the online help:
Enable Mapbox | PWA
If you wish to set an account for Google Maps, please follow instructions of the online help:
Enable Google Maps | PWA