The url scheme looks like this:
https://INSTANCE.TLD/feeds/c/COMMUNITY.xml
for example:
https://lemmy.sdf.org/feeds/c/sdfpubnix.xml
I really appreciate the flexibility of lemmy when it comes to the viewing experience, you can browse it through the web, through dedicated apps, through RSS feeds, &c. &c. This is the kind of openness, of choice and software, that I desire for every service on the web.