Cloudfare error response on requests

Hello, I’m working on an university project involving a proxy. I deployed both the frontend ( a nextJS app) the proxy ( a FastAPI app) and a NodeJS backend web service .
The requests from the frontend reach the proxy succesfully, but then the forwarded request to the backend service fails with the response below.

I have free plan so no access to internal host adresses for the service.
Anyone has any idea why this happens and how can i fix it ?! Any help is much appreciated.

Would switching to starter instance on the backend instance and using the internal address to forward the request solve this ?

Hi there,

Are you using any authentication between your frontend, proxy and backend?

Potentially moving the backend to be a private service may simplify things, and if it’s only ever needed to be accessible via the proxy, then it wouldn’t hurt.

Regards,
Keith

No authentication, is just a simple demo here : https://vulnerable-web.onrender.com .

I will wait a bit, maybe some staff will look into it, but if not i will go with a payed private service.

Hi there,

If you need further help, please open a support ticket with us so we can look more closely at your application.

Regards,
Keith

Opened thanks!