Allows to change shipment payer when creating TTN. Default value depends on option in plugin settings menu (in section Invoice).
Example of usage:
/** * @var string $payerType - Current shipment payer (provided from plugin settings) * @var \WC_Order $order - WooCommerce order for which TTN creating */ add_filter('wcus_ttn_form_payer_type', function ($payerType, $order) { return 'Sender'; }, 10, 2);
Available values for $payerType: Sender or Recipient
