There are several ways to link to a community. If your instance has had someone previously search for the community, then they will all work. If this hasn’t happened (usually because your instance is small or new) then there can be problems with the “shorthand” method that begins with an !. I’ve written a full explanation in this article at the Community Search Tips community. It lists the drawbacks and advantages of each approach that I’m aware of.
Hi there! Looks like you linked to a Lemmy community using a URL instead of its name, which doesn't work well for people on different instances. Try fixing it like this: !communitysearchtips@lemmy.ninja