.babelrc

{
  "presets": [
    [
      "@babel/preset-env",
      {
        "useBuiltIns": "usage",
        "corejs": 3,
        "modules": false
      }
    ]
  ],
  "plugins": [
      "@babel/plugin-proposal-class-properties",
      "@babel/plugin-proposal-optional-chaining"
  ]
}