Add a server in the Multiplayer menu with the above IP.
When adding the server, in addition to the IP, set the port to 25592 (only required with Bedrock Edition)
mc.leatplex.net:25592
144.217.29.210:25592
144.217.29.210
and the port 25592
If you still can't connect to the server, please check your internet connection. Our Minecraft server may also be temporarily down. Chances are it will work again in a few hours or even less.