Look in your building code first. Does the building / occupancy require sprinklers? If so, then an ambulance bay is not an area that is listed as exemption in NFPA 13 for sprinklers.
My same answer applies. What does the building code say about this area. If the building code requires, then you will need to protect in accordance with NFPA 13.
This sounds like you are describing maybe something similar to a porte cochere at a hotel. A covered spot where a vehicle is parked for drop-off and pick up. NFPA 13, 2016 edition states that a porte cochere should be protected per Ord Haz Grp I.
If it is a non-combustible canopy, the thought may have been the canopy is not used for the storage or handling of combustibles and that was used to exempt it from coverage.