Emper General Aviation (Suzhou) Co., Ltd., a Chinese carrier flying as ICAO code STJ and callsign KINGSMAN, currently has one aircraft, registered TWR with callsign STJARN, under live tracking.
Original report
airplanes.live
The listing highlights how live flight-tracking coverage is extending to smaller Chinese general-aviation operators alongside established business-jet fleets.
Emper General Aviation (Suzhou) Co., Ltd., a Chinese carrier operating under ICAO code STJ and radio callsign KINGSMAN, currently has one aircraft being tracked in real time. The tracked aircraft carries the callsign STJARN and registration TWR, with no altitude or speed data reported at the time of tracking.

AVI-GO, “Emper General Aviation (Suzhou) Operates One Aircraft Under Live Tracking”. https://ai.avi-go.com/news/ai-news-center/news-briefs/emper-general-aviation-suzhou-operates-one-aircraft-under-live-trackin-cf64a36d68a3658404ebb1bfd5aef1e0
Figures carry an explicit measurement window — cite the window shown on this page, not the date you retrieved it.