Like Trainguyrom wrote, you’re probably the first user on your instance trying to access it. Try the link again. It’s the proper way to link to communities using Lemmy. Your link doesn’t give people on other instances the easy option to subscribe to the community.
EDIT: Interestingly enough it looks like someone went through the first page of my profile and downvoted each comment of mine. Hmmm, how very strange ;P