$vars = array(
'PSPID' => $this->payment_params->pspid,
'orderID' => @$order->order_id,
'amount' => 100 * round(@$order->cart->full_total->prices[0]->price_value_with_tax, 2),
'currency' => $this->currency->currency_code,
'language' => $language,
'EMAIL' => $this->user->user_email,
'accepturl' => $return_url,
'declineurl' => $cancel_url,
'exceptionurl' => $cancel_url,
'cancelurl' => $cancel_url,
);
We could potentially turn it into an option of the plugin if you could provide more information on the name of that field and the possible values of the field.