Can Nginx proxy the Derper server?

I plan to deploy a DERP server in China, but due to Chinese laws and regulations, I have to adjust the “index.html” content of DERP server to include a registration number. I want to use nginx proxy link to return a page that meets the requirements when accessing “/”. For other requests, proxy to the DERP server.

Is anyone trying to do this? (using nginx proxy DERP server)
I’d like to know about possible problems.