In Beijing, ambulances from private organizations that meet the above conditions are usually assigned a Beijing license plate when they apply for registration, but not all of them are ambulances, as the Beijing license plate also includes private cars, cabs and other types of vehicles.
In summary, most of the private agency ambulances in Beijing are Beijing license plates, but this should not be used as the only criterion for distinguishing between an ambulance and a non-ambulance, and it is best to check to see if the vehicle has an official 120 Emergency Vehicle Operation License and related markings.