Cloudflare configuration for origin access protection

If you have cloudflare (or any CDN really) you want all your traffic to go through it to be able to protect the backend. No traffic should be hitting the backend directly. 

To prevent that from happening, we recommend you use mTLS

https://docs.upsun.com/define-routes/https.html#enable-mtls 

That will authenticate requests between the backend and cloudflare using a certificate.