Plutonium

Hello, yesterday I bought a root server and followed the steps to install a server on it. My root server has Ubuntu 18.04. When I look in the /root/ directory, there is a plutonium file that says " linux builds are broken for now ". Could someone help me and tell me what to do. and secondly when I use the command "wget ​​https://cdn.plutonium.pw/updater/plutonium -O plutonium &&
chmod + x ./plutonium &&
./plutonium -install-dir ./pluto "I get the output" ./plutonium: Line 1: linux: command not found
"and when I use the command" steamcmd + @ sSteamCmdForcePlatformType windows + login <STEA MUSERNAME> + force_install_dir ~ / server + app_update 42750 validate + quit
-bash " enter this as output " STEAMUSERNAME: file or directory not found "