With the new API major version, several endpoints have been removed and replaced by new endpoints.
The API version must be updated independently in the merchant backend.
Settings > Development > Open version management.
The status shows "Update available".
Click on Edit in the Actions column.
The API Major version should already be preselected. Simply click on Save .
Note: Once updated to the new version, this cannot be undone!
If there are several clients in a contracting company, these steps must be carried out for each client so that each client has the new API version.