Start using the service: https://cdnjs.cloudflare.com/polyfill
See the announcements from Cloudflare: https://blog.cloudflare.com/polyfill-io-now-available-on-cdnjs-reduce-your-supply-chain-risk + https://blog.cloudflare.com/automatically-replacing-polyfill-io-links-with-cloudflares-mirror-for-a-safer-internet.