Each time you click, the data is taken from the first element
for example, i have couple links with parameters
$(document).on('click', '.sitesubpay', function() {
var siteid = $('.sitesubpay').data('siteid');
var domaani = $('.sitesubpay').data('domain');
$('.getmymodal').click();
$("#domain").val(domaani);
$("#myModalLabel").text(' for ' + domaani);
console.log(siteid);
console.log(domaani);
var siteid = '';
var domaani = '';
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<a class="sitesubpay" data-siteid="2121" data-domain="domain1.com"><span class="label label-warning">pending payment </span></a>
<a class="sitesubpay" data-siteid="2122" data-domain="domain2.com"><span class="label label-warning">pending payment </span></a>
<a class="sitesubpay" data-siteid="2123" data-domain="domain3.com"><span class="label label-warning">pending payment </span></a>
but each click on any element, returns the data of only the first in the console.log
2121
domain1.com