Does anyone know how to do this for my server?

Which part specifically? The queue is a bunch of logic handling join requests and connecting as old users drop. The UI is done with deferrals, all the buttons and text and stuff are from the deferral. playerConnecting - Cfx.re Docs

I believe this is deferral cards. Have a look here: Adaptive Cards in deferrals - #13 by HassoNFTW