Why doesn't the hamburger animation work?

Question

css

I study only in js, maybe there is an error in it, until it reaches why it doesn’t work ....
There should be an animation flowing into a cross.
Codepen
I will be grateful for the help

Answer 1

1. jquery is not connected (Settings -> JavaScript -> Quick-add -> jQuery)
2. Misspelling in the class (.menu_link)
3. The toggleClass method waits for a class without a dot
4. It is better to move the js code to the js section, otherwise it will start executing before the libraries are connected