WordPress jQuery crash [closed]

The reason you are getting the error is that you are trying to bind a JavaScript function to a WordPress PHP hook.

Bind your JavaScript handler to the form’s submit event:

$( "#your-form" ).submit(function( event ) {

    //Select checkboxes by id
    var $checkboxes = $('input[id=checkboxprice]');
    //Set event
    $checkboxes.on('change', function () 
    {
        var totalPrice = 0;
        $checkboxes.each(function() 
        {
           //Sum values of checkboxes
           if(this.checked)
               totalPrice = totalPrice + parseInt(this.value);
        });
        $("#price").val(totalPrice);
    });  
    event.preventDefault();
});

Place the relevant code in a JavaScript file and enqueue it:

https://developer.wordpress.org/reference/functions/wp_enqueue_script/