Driver's Shoulder seatbelt

Does anyone know how I can fix my seatbelt which is stuck in the lock forward position? I have a 90 Toyota Camry. What caused It and how can I fix it.

Wiring. It's possible the wire in the driver's door is broken. My car has the same problem. I believe it's due to that the driver's door is opened more frequently than the passenger door. On the left of the driver's seet back, you can see a small rectangle cap, remove it and there is a knob you can turn to move the seat belt to back position.