Javascript button

Question

Pls help wth my javascript button
It says cant find variable
https://code.sololearn.com/W2w4chDT1aGl/?ref=app

Answer 1

//Working

Answer 2

//It is jquery, if you are running offline then maybe this errors occurs else on mine device all working

Answer 3

??? it says reference error cant find variable $ line five

Answer 4

ok