How long has the budgie been doing this?
Does he eat, drink and poop normally?
Is he active or lethargic?
Your budgie seems to have a pronounced tail bob in the video and that, along with the constant noise when he breathes, leads me to suspect he may have a respiratory infection.
Respiratory infections can be either viral or bacterial.
Viral infections do not respond to antibiotics so it is very important you get him to an Avian Vet for a proper diagnosis and treatment.
In the meantime, you can tent a sheet over his cage, fill a pot, kettle or crockpot with boiling water and set it outside the cage under the tent so the area fills with a warm steamy mist. If you have pure eucalyptus oil, put a drop of that in the water. The warm steam will help clear his airways so he can breathe more easily.
Good luck and please let us know how things progress after his vet appointment.