202001
Causes
This error occurs because the value of the AdditionalData parameter doesn’t correspond to the serialized JSON object expected by Klarna for the extra merchant data.
What to do
Ensure the data you are sending is in line with:
- The guidance provided in the Klarna article about which objects to include
- The example structure provided in Klarna’s documentation
Example
In the example below, the Create a Klarna PayIn request was attempted with a valid JSON format for AdditionalData, but not the serialized object expected by Klarna: