Unfortunately there is no easy fix for this. It is pretty common and most of the time the belt needs to be replaced.
I am attaching the process below on how to do this. Here is a guide that will help as well on how it works:
https://www.2carpros.com/articles/how-a-safety-belt-works
Let us know if you have questions. Thanks
Images (Click to enlarge)
Dec 21, 2020 at 7:46 PM