node main.js Error

[muhammadfapriandi]

[ipnet@rocketchat opt]$ node main.js
module.js:540
throw err;
^

Error: Cannot find module '/opt/main.js'
at Function.Module._resolveFilename (module.js:538:15)
at Function.Module._load (module.js:468:25)
at Function.Module.runMain (module.js:684:10)
at startup (bootstrap_node.js:187:16)
at bootstrap_node.js:608:3