The address is the first thing you need and the first thing people lose. It is shown in the panel on your server's main page, and it is also in the setup email you received when the server was created.
What to do
- Open your server in the panel
The address and port are shown together at the top of the console page, in the form
address:port. - Decide whether the port is needed
If the port is
25565, players can leave it out — the Minecraft client assumes that one. Any other port has to be typed in full. - Add it in the game
Multiplayer → Add Server. Put the address in the Server Address field exactly as the panel shows it, including the port if there is one.
The server appears in the multiplayer list with a green connection bar and the player count next to it.
The address does not change when you restart the server, so it is safe to share once and reuse.