I’ve checked the connections that are made when running extrepo enable librewolf command using tcpdump and it was accessing extrepo-team.pages.debian.net domain port 443, so I’ve configured passthrough for this connection and then it worked for me.
You can use tcpdump to check where is it connecting and then add the passthrough for this connection.
The PassThroughPattern value is a regex, \. is the escaped . and $ is the end of the line.
Now, after several weeks I need to give up here. Hopefully, someone finds a solution or workaround. Meanwhile, I need to switch to a new default browser.
… luckily Mullvad-Browser still have an old-schoolrepo.