Example

example2.php

<?php //Please do not include the opening PHP tag if you already have one

function tw_ee_ticket_selector_replace_qty_select_with_checkboxes() {
  wp_add_inline_script( 
    'ticket_selector',
    'jQuery( document ).ready(function($) {
        $(".tckt-slctr-tbl-td-qty select").each(function(){
            $(this).before("<input class=\'" + this.id + "\' type=\'checkbox\'>");    
            $(this).hide();

            $(".tckt-slctr-tbl-td-qty input:checkbox").change(function(){
                if(this.checked) {
                var select = $("#" + $(this).attr("class"));
                let value =  select.find("option:eq(1)").val();
                select.val(value).change();
                }
            }); 
        });
        $(".ee-ticket-selector-ticket-qty-th input:checkbox").change(function(){ 
            $(".tckt-slctr-tbl-td-qty input:checkbox").change();
        });
    });'
  );
}
add_action( 'wp_enqueue_scripts', 'tw_ee_ticket_selector_replace_qty_select_with_checkboxes', 11 );