wordpress - How to append() div to magnific popup window with jquery -

first knowledge give me in past years. need jquery , magnific popup in wordpress. try append div jquery magnific popup window, no luck me. useless code.

var sidebarx = $( "<div class='sidebarx'></div>" ); $(".mfp-content").append(sidebarx); 

and

$('.td-modal-image').on('click','a', function () { var sidebarx = $( "<div class='sidebarx'></div>" ); $(".mfp-content").append(sidebarx);  });  

i think problem how append() dynamically created elements. new jquery maybe else. thanks