How to fix App Proxy auth url 404 error?

[TuanDat]

I have the same problem with this post but i find no solution for it. So i want to re-ask about this topic

https://community.shopify.com/c/technical-q-a/app-proxy-url-not-working/m-p/625397#M16037

I have an app proxy with an url like that  mystore.myshopify.com/a/a/order that point on my server

When I load this url in browser my server is well call. Console network panel show me a 302 found and my Cli show me the console.log output I wrote for this endpoint.

With this console.log I return a body response "hello world" text too.  I want show it in the browser but instead on getting my blank page with this text staying on mystore.myshopify.com/a/a/order, the browser url is redirected to mystore.myshopify.com/auth?shop=mystore.myshopify.com and give me a 404 error.