The content not show

Hi, I has added the class “modal-link”, the modal windows was show, but without content…only show the load gif playing forever. I had try use internal and external link and both not working. So I try copy the code that was in FAQ to test, and this not work to. I dont know if Im missing something.

The code is:

<?php get_header(); ?>

<a class="modal-link" href="https://en.wikipedia.org/wiki/Apple" data-div="bodyContent">What is an apple?</a>

<?php get_footer(); ?>