Woocommerce modify required fields with ajax - php

Question

I added Woocommerce Billing Adress a fields like 'field_x" as required from child theme's function.php. And then added radio buttons with two option 'A and B' same page. I want to do that:
if user select radio option A, my custom fields will be invisible and 'not required'
if user select radio option B, my custom fields will be visible and 'required'
My sample code:
<?
// Adding fields and radios
add_filter('woocommerce_billing_fields', 'some_woocommerce_billing_fields', 10, 1);
function some_woocommerce_billing_fields($fields) {
$fields['radio_select'] = array(
'label' => __('Please select', 'woocommerce'),
'required' => true,
'clear' => false,
'type' => 'radio',
'options' => array(
'op_a' => __('op A', 'woocommerce'),
'op_b' => __('op B', 'woocommerce')));
$fields['field_x'] = array(
'label' => __('Field X', 'woocommerce'),
'placeholder' => _x('Field X', 'placeholder', 'woocommerce'),
'required' => true,
'clear' => false);
return $fields;
}
// PHP functions for Ajax calls
add_action('wp_enqueue_scripts', 'majax_enqueue_scripts');
add_action('wp_ajax_f_remove_req', 'f_remove_req');
add_action('wp_ajax_nopriv_f_remove_req', 'f_remove_req');
function majax_enqueue_scripts() {
$nonce = wp_create_nonce("nonce_t");
wp_enqueue_script('url', true);
wp_localize_script('url', 'urlm', array(
'ajax_url' => admin_url('admin-ajax.php'),
'nonce' => $nonce));
}
// Adding filter to remove require
function f_remove_req() {
if (!wp_verify_nonce($_POST['nonce'], 'nonce_t'))
die();
add_filter('woocommerce_process_myaccount_field_field_x', 'remove_reqs', 10, 1);
die();
}
// Removing require
function remove_reqs($field) {
$field['field_x']['required'] = false;
return $field;
}
// Add Ajax function
add_action('woocommerce_after_edit_account_address_form', 'address_script');
function address_script() {
?>
< script >
jQuery(document).ready(function () {
jQuery('#radio_select_op_a').change(function () {
jQuery('#field_x_field').hide();
jQuery.post(urlm.ajax_url, {
'action' : 'f_remove_req',
'nonce' : urlm.nonce
},
function (response) {
console.log(response);
});
});
jQuery('#radio_select_op_b').change(function () {
jQuery('#field_x_field').show();
jQuery.post(urlm.ajax_url, {
'action' : 'f_add_req',
'nonce' : urlm.nonce
},
function (response) {
console.log(response);
});
});
});
</ script>
<?
}
?>
i can add fields and ajax function is working.
But when i click "Save", php always sends filed_x->require option as true.
What is wrong? How can i do this?
Thank you.