Client certificate required

This public address only works with a valid device certificate. The browser either did not send one, or the certificate is not authorised for public access.

Use https://sonnenserver.fritz.box/ on the local network, or install / re-issue a client certificate via onboarding before using https://sonnen.casa/.
  1. On LAN, open https://sonnenserver.fritz.box/onboarding/ui.
  2. Trust the private CA: /ca.crt.
  3. Issue or re-issue the device certificate.
  4. Install it in the browser / system certificate store.
  5. Retry the public URL afterwards.

Missing certs and rejected certs both land here on purpose.