How to use the @fortawesome/free-brands-svg-icons.fab function in @fortawesome/free-brands-svg-icons

const path = require('path');
const prettyStringify = require('json-stringify-pretty-compact');
const shell = require('shelljs');
const YAML = require('js-yaml');

const fieldSchema = require('./data/presets/schema/field.json');
const presetSchema = require('./data/presets/schema/preset.json');
const nsi = require('name-suggestion-index');
const deprecated = require('./data/deprecated.json').dataDeprecated;

// fontawesome icons
const fontawesome = require('@fortawesome/fontawesome-svg-core');
const fas = require('@fortawesome/free-solid-svg-icons').fas;
const far = require('@fortawesome/free-regular-svg-icons').far;
const fab = require('@fortawesome/free-brands-svg-icons').fab;
fontawesome.library.add(fas, far, fab);

const request = require('request').defaults({ maxSockets: 1 });

let _currBuild = null;


function buildData() {
  if (_currBuild) return _currBuild;

  const START = '🏗   ' + colors.yellow('Building data...');
  const END = '👍  ' + colors.green('data built');

  console.log('');
  console.log(START);
  console.time(END);

module.exports = async () =>
  Object.keys(brands).map(iconKey => {
    const icon = fontawesome.icon(brands[iconKey])
    return {
      originalName: icon.iconName,
      source: icon.html,
      pack: 'fa-brands',
      verticalAlign: '-.125em',
    }
  })