Closure does not work

Tell us what’s happening:

Every item seems correct but it does not work! Why??
Thank you in advance.

Your code so far

function Bird() {
  let weight=10;

  this.getWeight = function(){
    return weight;

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.106 Safari/537.36.

Link to the challenge:

The original code has weight as 15.

function Bird() {
  this.weight = 15;

Try changing your value to 15.