I have to test and write up official instructions. But in the mean time here are the basic steps:
- Set up an account with Cloudflare. Free tier works fine.
- Add a site on Cloudflare. (this is your domain/subdomain).
- Turn on Always Use HTTPS and/or create a Page Rule which adds SSL Full for the domain.
- Change your host’s nameservers to Cloudflare’s.
I’ve been looking for a way to get https on custom domains for years and only came across this one when I signed up for Nolt - the very message board we’re using right now. They have some detailed instructions if you’re interested.