Maps supports two visual map editors. These editors work without installation of additional extensions and are not part of MediaWikis Visual Editor extension.
Leaflet editor (GeoJSON)
Wikitext editor (Special:MapEditor)
Maps comes with a visual editor that can create
#display_map wikitext. You can find this editor on Special:MapEditor.
You can paste the wikitext generated on the MapEditor special page on regular wiki pages.
The editor itself only supports Google Maps, though it can also create wikitext for Leaflet maps. This means you can only use this editor if you have your Google Maps API key configured.
Special:MapEditor has not gotten any updates for several years and is not actively maintained.