I need your emergency help. BOW FAULT BSİ SFR

friends, I had a transmission failure in my vehicle 2 days ago I got it today I received the diffrenasyal gears changed. everything good. When I bought the car alone, the date was reset? the next day I noticed my day LEDs do not work and I also get BOW FAULT malfunction in the vehicle airbag fault. Do you know, I want to reset your bsi brain right now. Could you please give information about how it's done? Regards

I think it was reset like this but I couldn't understand some things

http://www.bba-reman.com/content.aspx?content=citroen_bsi_body_control_failur to

I wonder which key is he talking about?