Why is my ip doesn't work?

Hello there I am confusing because, When I add my IP in the Multiplayer in minecraft, It doesn't work, it says that the server is offline but I turned the server on so I can test it.. so now I use the dynamic ip but I don't want that because maybe the players won't join because the Ip always changes when I restart the server.

The IP: IsaacTBeast.aternos.me

So it fixed now? Sir?