opencart-languagepack-finnish/catalog/api/coupon.php

<?php
// Text
$_['text_success']     = 'Success: Your coupon discount has been applied!';

// Error
$_['error_permission'] = 'Varoitus: You do not have permission to access the API!';
$_['error_coupon']     = 'Varoitus: Coupon is either invalid, expired or reached it\'s usage limit!';