When I checked your site, I didn't found as such link: http://prntscr.com/uo6bwr
So I am sharing this code which you have to add in wp-admin > wplms > footer > google analytics code with these script tags
In the code, I passed .button_login_trig so please pass the class of your link instead of this
<script>
jQuery("document").ready(function($){
$(".button_trig_login").on('click',function(event){
event.preventDefault();
$('a.smallimg.vbplogin').trigger('click');
});
});
</script>