In the tutorial to the right, you can see how easy it is to integrate using OIDC.
We've created a video tutorial as well as code examples, so you can get an overview how easy it is, while also utilizing the provided code examples
Please note that the example in the video does not include the required parameter merchant_vat in the /authorize call as demonstrated in step 1 here. The video was made before merchant_vat was made required. The vat number consists of country prefix (either FI or DK) and 8 digits.