Dear Mark,
configuration needed much troubleshooting so I'm sure I always restarted mailman core along apache2 but since it's still a testing environment, I took the liberty to test it again for you.
# pip install https://gitlab.com/mailman/hyperkitty/-/archive/1.3.5/hyperkitty-1.3.5.zip # pip install https://gitlab.com/mailman/mailman-hyperkitty/-/archive/1.2.0/mailman-hyperk... # systemctl restart mailman apache2 # tail -f /var/log/mailman/mailman.log /opt/hyperkitty_django/hyperkitty.log ==> /opt/hyperkitty_django/hyperkitty.log <== ERROR 2021-10-22 23:03:19,225 25973 hyperkitty.views.mailman The MAILMAN_ARCHIVER_KEY was not sent as the Authorization HTTP header. WARNING 2021-10-22 23:03:19,226 25973 django.request Unauthorized: /hyperkitty/api/mailman/archive WARNING 2021-10-22 23:03:19,226 25973 django.request Unauthorized: /hyperkitty/api/mailman/archive
==> /var/log/mailman/mailman.log <== Oct 22 21:03:19 2021 (26091) HyperKitty failure on http://127.0.0.1:8080/hyperkitty/api/mailman/archive: <html><title>Auth required</title><body> <h1>Authorization Required</h1><p>The archiver key must be sent over the Authorization HTTP header. </p></body></html> (401) Oct 22 21:03:19 2021 (26091) Exception in the HyperKitty archiver: <html><title>Auth required</title><body> <h1>Authorization Required</h1><p>The archiver key must be sent over the Authorization HTTP header. </p></body></html> Oct 22 21:03:19 2021 (26091) Traceback (most recent call last): File "/opt/mailman/venv/lib/python3.9/site-packages/mailman_hyperkitty/__init__.py", line 151, in _archive_message url = self._send_message(mlist, msg) File "/opt/mailman/venv/lib/python3.9/site-packages/mailman_hyperkitty/__init__.py", line 207, in _send_message raise ValueError(result.text) ValueError: <html><title>Auth required</title><body> <h1>Authorization Required</h1><p>The archiver key must be sent over the Authorization HTTP header. </p></body></html> # pip freeze | grep yperk HyperKitty @ https://gitlab.com/mailman/hyperkitty/-/archive/1.3.5/hyperkitty-1.3.5.zip mailman-hyperkitty @ https://gitlab.com/mailman/mailman-hyperkitty/-/archive/1.2.0/mailman-hyperk...
All the best, Marco