Ok. I went ahead and did a server wipe and tried again. This time I went with nginx as the webserver. Everything worked fine but I got the dreaded hyperkitty "auth required" error that Kelly mentioned in her walkthrough. However no matter how hard I tried to make sure the keys matched in mailman-hyperkitty.cfg and mailman-web.py, I kept getting the same error. However I noticed that a key was already there originally in mailman-web.py in the MAILMAN_ARCHIVER_KEY setting. So I decided to use that in mailman-hyperkitty.cfg and viola, it worked!
Also Kelly are you sure this is correct:
"There are two configuration files that have a key in them that must match for Hyperhitty to authorize and be able to store archives (the paths should be as follows): /etc/mailman3/mailman-hyperkitty.cfg (set the api_key without any quotes) /etc/mailman3/mailman-web.py (set the ‘SECRET_KEY’ - include single quotes around the key)"
It was the MAILMAN_ARCHIVER_KEY that I needed to make sure it was being matched by the API key in mailman-hyperkitty.cfg. I believe the SECRET_KEY setting has nothing to do with the auth errors that Hyperkitty was displaying.
Brian