Beautifulsoup and JavaScript Values

[Reldaing]

Hi, I'm trying to get a value from the soup that i created.
Here's what I found:

var next_chapter =  "https://www.lelscan-vf.com/manga/vinland-saga/165"

But the problem is that i would like to get the value from the "var next_chapter"
Here's what I tried(even if it's nonsense):

 a= soup.find('var next_chapter')

    NextUrl = a['var next_chapter']

Thanks for helping