Extract the KML polygons representing your LAS-order from Lantmäteriet.

getUsedPolygons.py

import xml.etree.ElementTree as ET
tree = ET.parse('las.kml')
root = tree.getroot()[0]
 
for pm in root.findall('{http://www.opengis.net/kml/2.2}Placemark'):
    if pm[0].text != "selected_square_style":
        root.remove(pm)
    else:
        pm.remove(pm[0])
 
        poly = pm[1]
        poly.remove(poly[0])
        poly.remove(poly[0])
        poly.remove(poly[0])
 
tree.write('out.kml')