Seat belt locked

Friends, I removed the child seat to clean the car, & nbsp; When I put it back, I noticed that the seat belt remained locked until the very end, it was locked until it was wrapped, there was no stretching, so it was not unlocked, then I removed the screw from the chassis so that I could loosen it, but it did not release it in the loosening mechanism. preventing it from coming off, that's the problem