Example of a Klarna checkout order with a voucher line item

klarna-order-with-voucher.php

<?php
$order = [
    'amount' => 88,
    'tax_amount' => 14.67,
    'currency' => 'GBP',
    'locale' => 'GB',
    'purchase_country' => 'GB',

    'notify_url' => 'https://developers.klarna.com/api/#checkout-api__ordermerchant_urls__validation',
    'return_url' => 'https://developers.klarna.com/api/#checkout-api__ordermerchant_urls__checkout',
    'terms_url' => 'https://developers.klarna.com/api/#checkout-api__ordermerchant_urls__terms',
    'validation_url' => 'https://developers.klarna.com/api/#checkout-api__ordermerchant_urls__validation',

    'items' => [
        [
            'type' => 'physical',
            'name' => 'Shirt',
            'quantity' => 1,
            'tax_rate' => 20,
            'price' => 100,
            'unit_price' => 83.33,
            'total_tax_amount' => 16.67,
        ],
        [
            'type' => 'discount',
            'name' => 'voucher code',
            'quantity' => 1,
            'tax_rate' => 20,
            'price' => -12,
            'unit_price' => -10,
            'total_tax_amount' => -2,
        ],
    ],
];