Select 以编程方式向电子商务管理计费字段添加选项

我想能够添加一个自定义属性时，添加一个新的管理秩序在Woocommerce。我添加了一个名为“许可证”的新帐单字段：

add_filter( 'woocommerce_admin_billing_fields' , 'admin_single_order_custom_addresses_fields' );
function admin_single_order_custom_addresses_fields( $fields ) 
{
  $fields_2 = array(); // Initializing
  foreach ( $settings as $field_key => $field_label ) 
  {
    $fields_2['license'] = array(
        'label'         => 'License',
        'show'          => '0',
        'type'          => 'select',
        'wrapper_class' => 'form-field-wide',
    );
  }

  foreach( $fields as $key => $field_data ) 
  {
      $fields_2[$key] = $field_data;
  }
  return $fields_2; // return sorted fields
}

当我将此新字段改为“文本”而不是“选择”时，我可以在为新订单选择客户时轻松更新值，方法是：

add_filter( 'woocommerce_ajax_get_customer_details' , 'add_custom_fields_to_ajax_customer_details', 10, 3 );
function add_custom_fields_to_ajax_customer_details( $data, $customer, $user_id ) 
{

     $data['billing']['license'] = "something"; 
}

但我希望“许可证”是一个选择字段，并使用“woocommerce\u ajax\u get\u customer\u details”更新该选择字段的选项。不知怎的，我一辈子都不能让它工作。我试过：

     $data['billing']['license']['options'] = array("something" => "somevalue"); 

$data['billing']['license'] = array(
    'options'          => array("something" => "somevalue"),
);

我试过：

     $data['billing']['license']['options'] = array("something" => "somevalue"); 

$data['billing']['license'] = array(
    'options'          => array("something" => "somevalue"),
);

但两者都没有更新新的“许可证”计费字段。我错过了什么