Received E-Mail about expiration date - How do extend the let’s encrypt certificate as nextcloud server is down and not available for a few days?

[Osiris]

@Rolf

So the renewal works after expiration date of the certificate (…)

Sure, the validation usually starts with HTTP (in the case of the http-01 challenge it does), so Let's Encrypt ignores invalid certificates if the initial HTTP request is redirected to HTTPS, as it doesn't add any security anyway.

@Rolf

(…) and the automatic renewal with setup the router hardware using the static IP for reaching my domain is possible.

I don't know what that means or how it's related to renewal, can you perhaps clarify?

@Rolf

I thought the renewal is also expired and not possible again afterwards.

"The renewal"?