portals on my velocity network?

hello how can I set up portals on the hub of my velocity server, so players can walk through them and go to the other worlds? I have been working at chatgpt all day today and yesterday trying to find answers but I could not find a plugin that 1 works with velocity and minecraft 1.21.5, 2 just has portals and not like all the lobby stuff, 3 that is free, and 4 one that can make portals and just doesnt add a command. it doesnt have to be a portal just a little spot will work but I really dont know what to do