Theyre two different softwares with two different apis, you can’t

The Lemmy and Mastodon services aren’t great at being interoperable. There’s at least one service out there that’s trying to interconnect all (or most) fediverse services, but I don’t remember enough about to turn up the the name in search.

You can only browse Lemmy communities through your Mastodon client (look at/follow @[email protected] where you see posts and replies) You need an account on a Lemmy server to be able to see this community from a Lemmy client.

I’m not sure that you can browse a Mastodon instance from a Lemmy client. I don’t think you can even browse a Lemmy instance from a different one (that is, see a foreign instance’s communities list, or browse their Local feed), only the individual users and communities.

But you can certainly browse a Mastodon user from Lemmy. Here’s you: https://programming.dev/u/[email protected]