Failed to update update-notifier, ModuleNotFoundError: No module named 'debian'

I'm trying to update update-notifier and update-notifier-common, but I got this error messages instead. What should I do to fix the broken update?

Setting up update-notifier-common (3.192.40.4) ...
Traceback (most recent call last):
  File "/usr/lib/update-notifier/package-data-downloader", line 24, in <module>
    import debian.deb822
ModuleNotFoundError: No module named 'debian'
dpkg: error processing package update-notifier-common (--configure):
 installed update-notifier-common package post-installation script subprocess returned error exit st
atus 1
dpkg: dependency problems prevent configuration of update-notifier:
 update-notifier depends on update-notifier-common (= 3.192.40.4); however:
  Package update-notifier-common is not configured yet.

dpkg: error processing package update-notifier (--configure):
 dependency problems - leaving unconfigured
Processing triggers for libglib2.0-0:amd64 (2.68.1-1~ubuntu21.04.1) ...
No apport report written because the error message indicates its a followup error from a previous fa
ilure.
      Override for key “direction” in schema “org.xfce.mousepad.state.search” in override file “/usr
/share/glib-2.0/schemas/20_xubuntu-default-settings.gschema.override” is outside the range given in 
the schema; ignoring override for this key.
Processing triggers for libglib2.0-0:i386 (2.68.1-1~ubuntu21.04.1) ...
Override for key “direction” in schema “org.xfce.mousepad.state.search” in override file “/usr/share
/glib-2.0/schemas/20_xubuntu-default-settings.gschema.override” is outside the range given in the sc
hema; ignoring override for this key.
Processing triggers for hicolor-icon-theme (0.17-2) ...
Errors were encountered while processing:
 update-notifier-common
 update-notifier
E: Sub-process /usr/bin/dpkg returned an error code (1)

There's this from 8 years ago that said to reinstall python-debian, but apt says the package is not available. I'm worried of doing the wrong thing with python installation because it seems like it'll be a big hassle to fix.

I'm on Xubuntu 21.04, if this is relevant.

You have to run

sudo apt-get update
sudo apt-get install --reinstall python3-debian

and then install all upgrades by using commands like

sudo apt-get --fix-broken install
sudo apt-get dist-upgrade