Fill fields with info is not working properly

Fill fields with info is not working properly

When the checkbox "Fill with auth user info" is clicked I want to populate the fields with the auth user info (name and surname) but it's not working. When the checkboxes are clicked is not working the fields are not populated with the auth user info. 

Do you know where is the issue?


What I have for now is in, https://jsfiddle.net/LahL166o/ the auth user info appears in this span


  1.   <span id="userData" data-name="John"
  2.         data-surname="Keane"></span>