I haven't tried but in principle you only need a Mastodon compatible authentication, there are other services that are not twitter clones. See for example https://fedi.tips/what-other-kinds-of-servers-are-on-the-fed... or more complete https://fediverse.observer/allsoftwares

I can't speak to other fediverse software but I tried a few lemmy servers to no avail. My mastodon instance is under maintenance so I guess I'll have to wait until that's done to sign up.