Hi! In the communities tab it will only display the communities that this instance has already interacted with (aka someone on this instance has subscribed to it)

A method I’ve used to find new communities is by going to https://browse.feddit.de and copying the community id (eg !main@toast.ooo) into the search bar

it may take a second for it to pull up the community in the search results, but once it loads you’ll be able to browse posts made to that community and subscribe to it