Use CodeMirror in Python Flask

Hi all!

I would like to try CodeMirror in Python Flask.

I’ve found a premade package but it seems not to work anymore (I just get errors if I follow the tutorial available here:

I’ve then decided to do the implementation on my own.

What should I do?
I tried copying the whole CodeMirror folder in my application and I’ve updated the 3 import rows with my paths and put those rows in the HEAD of my index file:

When I load the page I get in console this error:

javascript.js:10 Uncaught ReferenceError: CodeMirror is not defined
at javascript.js:10
at javascript.js:11
(anonymous) @ javascript.js:10
(anonymous) @ javascript.js:11

What am I doing wrong?

Thanks for your time and patience.