[tor-relays] Help with running a Tor Bridge

[Cor.ling]

Hi, I have set up a bridge on Kubuntu following this guide: https://community.torproject.org/relay/setup/bridge/debian-ubuntu/
In TODO1 I put: 443 and in TODO2: 80 (I used these values only because they were in the example).

But in my log (/var/log/syslog) I'm seeing these errors:
Tor[X]: Your server has not managed to confirm reachability for its ORPort(s) at X.X.X.X:443. Relays do not publish descriptors until their ORPort and DirPort are reachable. Please check your firewalls, ports, address, /etc/hosts file, etc.
Tor[X]: Unable to find IPv6 address for ORPort 443. You might want to specify IPv4Only to it or set an explicit address or set Address. [60 similar message(s) suppressed in last 3600 seconds]

How can I resolve them? And also: how can I enable IPv6?
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