I created a .env file and put this inside of it:
VUE_APP_TEST='Hello'
Then in one of my components I tried console.log(process.env.VUE_APP_TEST), however, I get undefined in the console.
Not sure if this matters but to create the project I'm working for, I've used vue webpack-simple template.
I've seen a couple of articles and tutorials in which what I've already done works just fine, however, not so much in my case.