How do I add a class to interactive video links?

I am using the H5P Wordpress plugin and am trying to add a class to all H5P interactive video links.
This is what I have so far:

H5P.jQuery(document).ready(function () {

  // Listening for interactive video element 
  
   if(H5P.jQuery('.h5p-interactive-video').length > 0)
      H5P.jQuery('.h5p-link a').addClass("modal-link");

});

How do I listen for the video to be loaded? My current script can't find the links because they don't exist yet.

Wordpress - Follow up question:
I am trying to load the links in a modal overlay. The code for the overlay is provided by a H5P unrelated plugin. Will that plugin work in H5P? 

UPDATE:

I was able to add classes to those dynamically added links in the interactive videos in the following way:

if (H5P && H5P.instances[0] && H5P.instances[0].libraryInfo.machineName === 'H5P.InteractiveVideo') {

	H5P.jQuery(document).on('DOMNodeInserted', function(e) {

		if ( H5P.jQuery(e.target).find(".h5p-link-interaction") ) {
				H5P.jQuery(e.target).children("a").addClass("modal-link");
		}
	});
}