Enter the name and population of the city above, then list the coordinates. Coordinates can be obtained this way:

1. In QGIS open QuickOSM (green magnification glass)
2. Key=boundary, Value=administrative, enter city name, Run
3. Select city polygon, Vector - Geometry Tools - Simplify // use 0,005
4. Edit mode (pencil), Vertex tool
5. Mouse right-click on layer to lock it, hold mouse left button to select vertices, Del to remove unneeded vertices (outer boundaries)
6. Vector - Geoprocessing Tools - Dissolve (Advanced Options - Skip (ignore) features with invalid geometries)
7. Processing Toolbox - search for "vert", select Extract vertices
8. Select extracted vertices layer, mouse right-click, Export - Save Features as
9. CSV, filename, deselect all, Layer Options - Geometry - AS_YX
10. Paste the list of coordinates from the CSV into the field on the right.