The credentials could not be verified. The request to the Deutsche Post API failed. Error: Unknown user or invalid password
If you create shipping labels via Deutsche Post and receive an error message when checking the credentials, even though the details are correct, in many cases the approval of the Pickware application is missing in your Deutsche Post Portokasse account.
The error message from Deutsche Post simply states that the credentials are incorrect, even if only the approval is missing.
Without this approval, no labels can be created – even if the username and password are correct.
Cause
Deutsche Post requires a one-time approval of the application used in the Portokasse account in order to use its interface. If this approval has not yet been granted, the interface returns a generic error that is technically indistinguishable from incorrect credentials.
This approval may also need to be granted again after, for example, an adjustment to the API by Deutsche Post, even though it was already granted before.
Solution: Approve Pickware in the Portokasse
Open Settings → Extensions → Deutsche Post in your Admin.
Click on "Check credentials". You will then receive an error message.
Then log in to your Portokasse account:
https://portokasse.deutschepost.deOpen the Open approvals section.
Confirm the approval. You may receive an email with a confirmation code to verify your identity.
Then switch to the Business applications tab.
Open editing mode via the pencil icon.
Approve our Pickware application and save the setting.
Return to Pickware and check the credentials again.
After successful approval, both the credential check and the creation of shipping labels will work as usual again.