regeneratorruntime is not defined

# First install the package
yarn add babel-polyfill --dev
# or
npm add babel-polyfill --dev
# Then require it in the angular.json
"scripts": ["node_modules/babel-polyfill/dist/polyfill.min.js"]// In package.json add 
{
...
  "browserslist": {
    "production": [
      ">0.2%",
      "not dead",
      "not op_mini all"
    ],
    "development": [
      "last 1 chrome version",
      "last 1 firefox version",
      "last 1 safari version"
    ]
  }
  ...