Currently the FMHY lemmy instance is down, they will likely create a new one at lemmy.fmhy.net in the coming days. You can create an account on any Mastodon instance (for example, mastodon.social), search for the user @fmhy, and follow them for updates on when it will be up and how to register.
How to join FMHY community?
I tried to join the lemmy instance some weeks ago but the registration was likely not approved, even though I remember I did everything right....