I made a script that "transfers" your reddit subs to lemmy by searching for communities with the same name and joining them.

I started working on this when I moved my main account/traffic from reddit to lemmy and with the help of some people I improved it and fixed some bugs.

One thing that annoyed me about moving to Lemmy was that I'd lose my subreddits and that looking for and joining communities on Lemmy would be tedious. So (logically) I spent 2 days writing a script, that gets a list of your subreddits from your reddit account and looks for communities with the same name on Lemmy. It also joins those communites. So all you have to do is download, enter your credentials and you're done.

https://github.com/induna-crewneck/Reddit-Lemmy-Migrator/