Add Klarna

Klarna payment and shopping services.

README.md

@@ -558,6 +558,7 @@ API | Description | Auth | HTTPS | CORS |
 | [IEX Cloud](https://iexcloud.io/docs/api/) | Realtime & Historical Stock and Market Data | `apiKey` | Yes | Yes |
 | [IG](https://labs.ig.com/gettingstarted) | Spreadbetting and CFD Market Data | `apiKey` | Yes | Unknown |
 | [Intrinio](https://intrinio.com/) | A wide selection of financial data feeds | `apiKey` | Yes | Unknown |
+| [Klarna](https://docs.klarna.com/klarna-payments/api/payments-api/) | Klarna payment and shopping service | `apiKey` | Yes | Unknown |
 | [Mono](https://mono.co/) | Connect with users’ bank accounts and access transaction data in Africa | `apiKey` | Yes | Unknown |
 | [Moov](https://docs.moov.io/api/) | The Moov API makes it simple for platforms to send, receive, and store money | `apiKey` | Yes | Unknown |
 | [Nordigen](https://nordigen.com/en/account_information_documenation/integration/quickstart_guide/) | Connect to bank accounts using official bank APIs and get raw transaction data | `apiKey` | Yes | Unknown |