NEED a JAVASCRIPT EXPERT

The job is simple. I have a video for it. The employee has to be EXTREMELY GOOD WITH JAVASCRIPT. The job is to fix a logger or webextension that is based on Firefox. It collects data from the facebook. The problem is i get a message now on the console " the link is null" and stops collecting data. Requirement: 1) You need to install firefox 2) you need to have your own facebook account to test my software 3) you need to sign NDA How to load the software: After installing firefox, you have to type one the browser "about:debugging". Then click on temporary add-ons. Click on [login to view URL] file to load the logger Open up your facebook account and click on the logger symbol to press start twice to run the logger I will send the video for you to show you the problem i am having