2003 model 206 XT airbag light

My friend has a 2003 model 206 XT. While driving on the road at night, the battery light flashes first, then all the indicators are gone, parked the car anyway, and when it comes back the car does not work. When it comes to the morning, they take the electrician with him and take the car to the electrician. He buys the car, but there is something he does not notice, or rather, he realizes late. 2 airbag lights are constantly on. I wanted to consult you without taking it back to the electrician. Why would this problem happen? The forum says that it was extinguished under the steering wheel, but our problem is not there but you can give an idea.