Contrarian Problems Click on a link to with Php, Jquery

Good morning, I have been reviewing a page and they asked me to do a job that every time you click on a specific tag, click on a database, when you click open a modal that is obtained by jquery or ajax. . I do not understand much about ajax but I would like to know how to do it with these codes. Thanks

HTML code

<a  href="#" class="citar-documento" title="Citar documento" ></a>
 .......
 .......

 <script>
  $('.citar-documento').click(function(){
    $.confirm({
    'title'     : 'Cita en formato APA 6ta., versi&oacute;n',
    'message'   : 'Durán, A. (2018) Las encrucijadas en el arte mexicano. <i>Espacio I+D Innovación más Desarrollo, 7</i>(17) 30-44.',
    'articulo'         : 'a2', /* a1 = numero de articulo, r15 = no. revista, v6= volumen 6, borrar este comentario al final de la edición */
    'idcita'    :'114',
    'buttons'   : {
        'Cerrar'    : {
            'class' : '',
            'action': function(){}//Sin actividad...
            }
            }
        });
    });

  </script>

Js

(function($){

    $.confirm = function(params){

        if($('#confirmOverlay').length){
            return false;
        }

        $dato = params.idcita;
        window.location.href = "../../../citas.php?count_cita="+$dato;
    };


}
)(jQuery);