https://ridelikeaninja.com/wp-content/plugins/woocommerce-follow-u…/templates/js/fue-front.js?ver=4.9.51

1(function($) {
2    var email_fields = ["input#billing_email"];
3
4    for ( var el in email_fields ) {
5        var $field = $( email_fields[el] );
6
7        $field.on( 'change', [el], update_user_email );
8    }
9
10    function update_user_email( event ) {
11        if ( FUE_Front.is_logged_in ) {
12            return;
13        }
14
15        var email = $(event.target).val();
16        var first_name  = $("#billing_first_name").val();
17        var last_name   = $("#billing_last_name").val();
18
19        $.post( FUE_Front.ajaxurl, {
20            action: "fue_wc_set_cart_email",
21            email: email,
22            first_name: first_name,
23            last_name: last_name
24        });
25
26    }
27})(jQuery);