How do I request city boundary data from Google Maps?

Question

OpenStreetMap

Actually, the question is in the title. Interested in analog wiki.openstreetmap.org/wiki/Nominatim
That is, to request and get the coordinates of the polygon.

"geojson":{"type":"Polygon","coordinates":[]}

Nominatim suits everyone, except for the incompleteness of the data (specifically, data for Canada are of interest). For example, Google Maps knows about the districts of Ontario and highlights them, but OpenStreetMap does not. It is the same for some cities - where OpenStreetMap shows a point, there Google maps show the full boundaries of the city / district.
Other alternatives are also suitable, the main thing is the completeness of the data.