When reloading the config, I get
Failed to perform the action homeassistant/reload_all. Cannot quick reload all YAML configurations because the configuration is not valid: Invalid config for 'http' at configuration.yaml, line 17: not a file for dictionary value 'http->ssl_certificate', got '/ssl/fullchain.pem' Invalid config for 'http' at configuration.yaml, line 18: not a file for dictionary value 'http->ssl_key', got '/ssl/privkey.pem'
Checking the DuckDNS integration log, I get
s6-rc: info: service s6rc-oneshot-runner: starting
s6-rc: info: service s6rc-oneshot-runner successfully started
s6-rc: info: service fix-attrs: starting
s6-rc: info: service fix-attrs successfully started
s6-rc: info: service legacy-cont-init: starting
s6-rc: info: service legacy-cont-init successfully started
s6-rc: info: service duckdns: starting
s6-rc: info: service duckdns successfully started
s6-rc: info: service legacy-services: starting
s6-rc: info: service legacy-services successfully started
[18:30:18] INFO: Starting DuckDNS...
[18:30:18] WARNING:
So something went wrong, but I'm not sure what I can do to fix it when the warning is empty ? Restarting DuckDNS doesn't help.