config( 123456, // Merchant ID 'sharedSecret', // Shared Secret KlarnaCountry::SE, // Country KlarnaLanguage::SV, // Language KlarnaCurrency::SEK, // Currency Klarna::BETA, // Server 'json', // PClass Storage '/srv/pclasses.json', // PClass Storage URI path true, // SSL true // Remote logging of response times of xmlrpc calls ); // OR you can set the config to loads from a file, for example /srv/klarna.json: // $k->setConfig(new KlarnaConfig('/srv/klarna.json')); /** * 2. Calculate the monthly cost for the product page. */ $sum = 149.99; // Let's assume this is the product cost. $flag = KlarnaFlags::PRODUCT_PAGE; // or KlarnaFlags::CHECKOUT_PAGE, if you want // to do it for the whole order. $pclass = $k->getCheapestPClass($sum, $flag); // Did we get a PClass? (it is false if we didn't) if ($pclass) { // Here we reuse the same values as above: $value = KlarnaCalc::calc_monthly_cost( $sum, $pclass, $flag ); echo "Value: {$value}\n"; /* $value is now a rounded monthly cost amount to be displayed to the customer. */ }