Javascript Referenceerror: Tl Not Defined Even Though It's Explicity Defined In *.js File

I'm working on trying to utilize a local implementation of the Timeline JS tool by Knight Laboratories by following these instructions. Because my use cases will require JSON to be

Solution 1:

@melpomene asked the right question in the comments about and got me looking to see if the JS file was being loaded. The answer is that it was not because the url provided in the <script> tags was not valid. Adding "https:" to the beginning of both urls got the code to work.

The reason TL was not defined is because the JS file was not loading due to a faulty url.