Depends on how you're interacting with Lemmy, I think. In firefox I click on the thumbnail. In Jerboa I have to enter the comments thread, or follow the link by tapping on the thumbnail.
You might find more knowledgeable answers in the Lemmy support community.
ahh ok, I just created my acc exactly 10 minutes ago via FMHY community and still figure thing out, btw did you why I can't create acc on other community it's just stuck on loading forever, I mean I already have an acc now but that's very odd
It probably would be a problem with the servers if it's stuck on loading.
But you shouldn't need to create accounts on multiple instances: if the instances are federated, that is if they have linked, you should be able to subscribe and interact with communities on other instances just from your one account.