You can call you insurance company but there is a good chance you will get misinformation. You can ask your doctor but many times he is not sure what equipmnet company the company has changed to. As the user it may require someone to help you navigate 5he system. Your sleep lab may help. If they cannot finding a helpful sleep tech or sleep coach may be your best option.
There are people out there who will sp3nd the time finding out what you need., asking physicians for documentation and asking the insurance companies what they will require to pay.
There is help and you shpuld not heaitatw to ask for it. We want you to use your equipment and to feel comfortable.