The easiest to explain method:
- Copy the link https://sh.itjust.works/c/plugins
- Paste it to search box at lemmy.ml
- The search results open the foreign sub while staying in your own instance
- Subscribe
The other way:
Click this link to skip some of the steps above:
https://lemmy.ml/c/[email protected]
Look how I made this link, you can do the same for other subs too.