The following example retrieves the current sky chart for an observer located at Paris (48.8534°N,2.34880°E,39m) on July 5th 2020 at 0h00 (French legal time).
https://opale.imcce.fr/api/v1/chart/sky?date=2020-07-05T00:00:00×cale=Europe/Paris&observer=48.8534,2.34880,39&map-center=180,90&map-constellation-link&map-constellation-label&map-cardinal-points&map-zenith&map-labels=fr&map-solarsystembodies-label&image-style=astaf&map-observer=name,coord&map-time&magnitude-limit=5.5&map-milkyway