Issue with env vars using webpack

Hi there!

I'm trying to deploy a Vue2 project using vue-cli.

To access my env vars on client-side code i need to use process.env.VUE_APP_MYVAR
But on railway, everything returns undefined?

Its gets my process.env.NODE_ENV var, but it doesnt get my other vars.
Tried using webpack-dotenv to expose system vars too, but the rest of my vars still undefined.

const Dotenv = require('dotenv-webpack');
new Dotenv({
                systemvars: true

What could it be? Webpack messing it up? On AWS worked fine.