Running locally is something we hear a lot of - typically though locally isn’t a Linux server, so it’s not a direct comparison.
I suspect the problem here is in app.js and specifically a difference between the require statement you have for login.js - you need to make sure that the require statement is referencing the paths/files IDENTICALLY as to their names on disk - Linux is a case-sensitive operating system, so if you had require('./authRoutes/Login.js in your app.js, but your filename was login.js then you would get MODULE_NOT_FOUND just as you are here.
Your require will be ./authRoutes/login.js so the folder should be named authRoutes and the file login.js