Restrict the maximum number of checkbox addon user can select in the frontend

function.php

add_action('wp_footer','scripting');
function scripting()
{
    ?>
    <script type="text/javascript">
        // console.clear();
        // console.log("started check box condition");

		jQuery(document).ready(function($){	
	        var max_selection=2;    // change this value
	        jQuery(document).on('click', '.single_add_to_cart_button', function (e) {
	        // console.log("inside check box condition");
	            // alert("Start");
	            jQuery(this).removeClass('loading');
	            jQuery('.required_checkbox').removeClass('required_checkbox');
	            jQuery('.required_radiobutton').removeClass('required_radiobutton');
	            jQuery('.required_addons').removeClass('required_addons');
	            jQuery('.required_addons').removeClass('colour_options_addons');
	            var cart_button=this;
	            var i=0
	            jQuery('.ph_check_box_addons').each(function(){
	                current_div=this;
	                if(jQuery(this).attr('data-required')==1 && !jQuery(this).closest('.ph-addon-container').is(':hidden'))
	                {
	                    var num_elements_selected = jQuery(this).find('.phive-addon-checkbox:checked').length;
	                    if(num_elements_selected>max_selection || num_elements_selected==0)
	                    {
	                        // jQuery(this).addClass('required_checkbox');
	                        jQuery(this).closest('.ph-addon-container').addClass('required_addons');

	                        // if(jQuery(this).hasClass('loading'))
	                        // {
	                            jQuery(cart_button).removeClass('loading');
	                        // }
	                        i++;
	                        jQuery(current_div).closest('.ph-addon-container').focus();
	                    }
	                    if(num_elements_selected>max_selection)
	                    {
	                    	name=jQuery(this).closest('.ph-addon-container').find('label').html();
	                        name=name.replace('<span class="required_star">*</span>',"");
	                        name = name.replace(/\n/g, "");
	                        name = name.replace(/\s\s+/g, ' ');
	                        name = name.replace(/  +/g, ' ');
	                        alert("Maximum allowed selection for "+name+" is "+max_selection);
	                    }
	                }
	            });
	            if(i>0)
	            {
	                jQuery('.required_addons').first().focus();
	                e.preventDefault();
	                return false;
	            }
	        });
		});
    </script>
<?php
}