How to calculate the exact value of dashoffset and dashoffaray?

Question

JavaScript

I tried in two ways, but nothing comes out in the console. No errors:

function TotalLength(){
  var path = document.querySelector('#check');
  var len = Math.round(path.getTotalLength() );
  alert("Длина пути - " + len);
};

var path = document.querySelector('.squiggle-container path');
console.log(path.getTotalLength());