How to make Font awesome 5 work with webpack

I’m trying to use Fontawesome in my Flask/webpack project.

The craziest thing is some point it worked then stopped, I changed something stupid, it worked again and finally it stopped working completely.

What I have:

package config:

  "devDependencies": {
        ...
        "css-loader": "^1.0.0",
        "node-sass": "^4.9.3",
        "sass-loader": "^7.1.0",
        "style-loader": "^0.23.0",
        "webpack": "^4.19.0",
        "webpack-cli": "^3.1.0",
        "webpack-merge": "^4.1.4"
    },
    "dependencies": {
        "@fortawesome/fontawesome-free": "^5.3.1",
        "bootstrap": "^4.1.3",
         ...
    }

webpack config (rules section):

   test: /.(ttf|otf|eot|svg|woff(2)?)(\?[a-z0-9]+)?$/,
        use: [{
            loader: 'file-loader',
            options: {
            name: '[name].[ext]',
            outputPath: '../fonts/',  
            publicPath: '../static/fonts' 
            }
        }]
    },
    {
        test: /\.css$/,
        use: [
            'style-loader',
            'css-loader',
            'sass-loader'
        ]
    },
    {
        test: /\.scss$/,
        use: [
            "style-loader", 
            "css-loader", 
            "sass-loader" 
        ]
    },

webpack, entry section:

entry: {
        myStyles: './stles/myStyles.js'
    },

myStyles.js:

import fontawesome from "@fortawesome/fontawesome-free/scss/fontawesome.scss";
import regular from "@fortawesome/fontawesome-free/scss/regular.scss";
import solid from "@fortawesome/fontawesome-free/scss/solid.scss";
import brands from "@fortawesome/fontawesome-free/scss/brands.scss";

fontawesome.library.add(solid, regular, brands) 

The last line though caused the error in Chrome:

Uncaught TypeError: Cannot read property 'add' of undefined

I also tried to add imports into my entry scss and it worked at some point, then stopped:

$fa-font-path: '~@fortawesome/fontawesome-free/webfonts';
@import "~@fortawesome/fontawesome-free/scss/fontawesome";
@import "~@fortawesome/fontawesome-free/scss/regular";
@import "~@fortawesome/fontawesome-free/scss/solid";
@import "~@fortawesome/fontawesome-free/scss/brands";

So, finally in my template I have:

<i class="fas fa-user-circle fa-fw"></i>

and what I see is only squares.

I checked Chrome, fonts are loaded (ttf, woff, woff2).

Please help. I already spent more than 6(!!!!) hours wasted on this problem and it’s more than I spent on anything else related with webpack.

UPD I think I figured it out. I found that my public path was wrong, I mean this part of webpack config: publicPath: ‘../static/fonts’ – it currently points to the static/fonts folder one level up from my html. First of all, relative path is wrong per se, secondly, a relative path will not work for other folders, third, I’ve changed it to the relative to the root: ‘/static/fonts’ and it worked.