This is an important discussion regarding airbag & seat belts. The car is equiped with impact sensors and car seats have weight sensors inside them. So in case of an impact both impact & weight sensors signal SRS system to deploy the airbag regardless of seatbelt position.
If the seatbelt is ON then what SRS system does is it locks the belt for a few seconds to avoid the driver & passenger fly out of the windshield as the airbags are expected to deploy regardless seat belt is worn or not.
Even though seat belt is not Worn, Airbags should deploy as the SRS system gets signals from Impact sensors & Car Seat Sensors.
My friend had an accident in 2017 civic. Both the driver & passenger were not wearing seat belts but their airbags popped. Luckily they survived the accident & Alhamdulliah doing fine.
Best of Luck, May Allah protect us all.