Question regarding CDL Air Brake test

Hi everyone, I am currently going for my Class B CDL road test in a few days. I have a question regarding the air brake test. For the parking brake test, I need to put the vehicle in drive with the parking brake on to test that the parking brake is working properly. However, the Freightliner 114SD (Automatic Allison transmission) truck that I am using for the test requires for the service brake pedal to be depressed in order for the truck to shift into drive and allow me to tug against the parking brake. If I try to put it into drive without depressing the brake pedal it will say “D-N” and it’s not actually in gear. If I release the brake, and put it into Drive and then reapply the parking brake it also says “D-N.” My question is if I press the pedal to put It into drive while the spring brake is applied, will I fail? Or do all automatic trucks require for you to apply the service brake pedal for the truck to go into gear? Not sure if this is common sense so I apologize ahead of time. Thanks for your help!