Our website states for security level 2:

The key was automatically delivered by the mail domain owner (the provider) via HTTPS. This is only possible if the provider uses the WKD (Web Key Directory) service

This works, but can also be triggered by manual import + certification of an openpgp key:

1. Download my cert:

2. Make sure, the cert is not in keyring
3. Import my cert in Kleopatra (e.g. drag and drop)
4. Select Certify and certify all uids
5. Open Outlook
6. Check the security level of ted:INBOX/Sicherheitslevel/2 security levle2 (wkd) => level 2