NextcloudPi - Let's Encrypt Error

Wo muss ich die DNS A/AAAA record(s) eintragen (/etc/host)?

Bisheriger stand:
NextcloudPi läuft im Netzwerk und im Internet auch schon mit einer Domain.

Fehlermeldung:

[ letsencrypt ] (Sun Apr 17 10:25:58 CEST 2022)
Saving debug log to /var/log/letsencrypt/letsencrypt.log
Plugins selected: Authenticator webroot, Installer None
Requesting a certificate for <domain>.duckdns.org
Performing the following challenges:
http-01 challenge for <domain>.duckdns.org
Using the webroot path /var/www/nextcloud for all unmatched domains.
Waiting for verification...
Challenge failed for domain <domain>.duckdns.org
http-01 challenge for <domain>.duckdns.org
Cleaning up challenges
Some challenges have failed.
IMPORTANT NOTES:
- The following errors were reported by the server:

Domain: <domain>.duckdns.org
Type: connection
Detail: Fetching
http://<domain>.duckdns.org/.well-known/acme-challenge/cuVKFOXFf3j3-vN_qJsebhBIH3nRu4R7CwGyduGk6Ec:
Timeout during connect (likely firewall problem)

To fix these errors, please make sure that your domain name was
entered correctly and the DNS A/AAAA record(s) for that domain
contain(s) the right IP address. Additionally, please check that
your computer has a publicly routable IP address and that no
firewalls are preventing the server from communicating with the
client. If you're using the webroot plugin, you should also verify
that you are serving files from the webroot path you provided.

Timeout during connect (likely firewall problem)
Port 80 ist für http und Port 433 für https offen. Wo könnte das Problem liegen?

To fix these errors, please make sure that your domain name was
entered correctly and the DNS A/AAAA record(s)
Daten stehen im Format: in /etc/host

check that your computer has a publicly routable IP address
Hat er, ich kann ihn unter dieser auch mit Domain aufrufen.

Infos:
NextcloudPi version: 1.47.1

Werden beide Ports auch vom Router auf die jeweiligen Ports der Nextcloud-Instanz weitergeleitet?