Alternative map services

Google offers $200 free monthly usage, that's 100,000 maps loads a month.

Changing the service used is as simple as editing the URL used inside "js/fileman/infopanel/details_panel.js" (search for "google.com" and remove the condition that checks for a configured "Settings.google_static_maps_api_key").

We welcome suggestions for alternative services. So far I haven't found a better one than Google's.

Thank you very much, this solution is enough for me.

I replaced google maps to yandex because it do not need a key. I found a short comparison of websites with the maps (overview-of-static-map-solutions) but probably none is better than google maps. Are you planning to add additional features related to the map? It would be nice to browse photos pinned to map.
Regards

I  can suggest Arcgis API, you can see this article

Migrating from Google Maps JavaScript API to ArcGIS API for JavaScript
https://developers.arcgis.com/javascript/latest/guide/migrating-from-google-maps-to-arcgis-javascript-api/index.html
Google has returned some of these customers to ESRI

Regards

I'm a fan of leafletjs using data provided by MapBox. Easy to implement, looks good, free up to 50,000 map views a month, and adds some interactivity like zooming or moving the map as well.