honestly it’s pretty egregious that it hasn’t been done by now… i know nobody is getting paid much if anything to maintain this site but secure login is like step one of setting up a website.
Ran a WHOIS check and saw that this is running in DigitalOcean. If they also manage the domain name, it should be pretty simple to enable a Let’s Encrypt cert.
As another sidenote, I recommend as a general best practice to use a randomized password for all of your website logins regardless of TLS. As far as password managers are concerned, I highly recommend Bitwarden.
Because many of your users rely on untrusted networks for connectivity, and really dont like being subject to javascript injections while connected to hotel, coffee shop, airline, and pub networks.