Beaver builder doesn't load on a single page after adding custom script

Hello there,

I have added a custom script for a single page and after reloading the page to see if the script works fine (on local it worked but without Beaver), the Beaver Builder doesn’t load any more so I am not able to amend / fix / remove the script that causes the problem.

Any ideas where I can enter the js file for this single page? Where does it live?

I tried via WordPress admin panel but did not find the way in. Is it possible to find the file including this script from a hosting (cPanel)?