📒 docs: Document usage of reverse proxies for SendEarlyHints

docs/api/ctx.md

@@ -2176,6 +2176,7 @@ resources while the server prepares the full response.
 :::caution
 This feature requires HTTP/2 or newer. Some legacy HTTP/1.1 clients may not
 Early Hints (`103` responses) are supported in HTTP/2 and newer. Older HTTP/1.1 clients may ignore these interim responses or misbehave when receiving them.
+See [Enabling HTTP/2](../guide/enabling-http2.md) for instructions on how to use a reverse proxy (e.g. Nginx or Traefik) to enable HTTP/2 support.
 :::
 
 ```go title="Signature"

docs/guide/enabling-http2.md

@@ -0,0 +1,72 @@
+---
+id: enabling-http2
+title: Enabling HTTP/2
+description: >-
+  Learn how to enable HTTP/2 (and optionally HTTP/3) in Fiber using reverse
+  proxies like Nginx or Traefik. Required for features such as SendEarlyHints
+  and other modern HTTP capabilities.
+sidebar_position: 4
+---
+
+## Enabling HTTP/2
+Some features in Fiber, such as SendEarlyHints, require HTTP/2 or newer.
+If your app is served directly over HTTP/1.1, certain features may be ignored or not function as expected.
+
+To enable HTTP/2 in production, you can run Fiber behind a reverse proxy that upgrades connections.
+Popular choices include Nginx and Traefik.
+
+Example for Nginx
+```go title="Example"
+server {
+    listen 443 ssl http2;
+    server_name example.com;
+
+    ssl_certificate     /etc/ssl/certs/example.crt;
+    ssl_certificate_key /etc/ssl/private/example.key;
+
+    location / {
+        proxy_pass http://127.0.0.1:3000;
+        proxy_http_version 1.1;
+        proxy_set_header Connection "";
+        proxy_set_header Host $host;
+    }
+}
+```
+This configuration enables HTTP/2 with TLS and proxies requests to your Fiber app on port 3000.
+
+Example of Traefik
+```go title="Example"
+entryPoints:
+  websecure:
+    address: ":443"
+
+http:
+  routers:
+    app:
+      rule: "Host(`example.com`)"
+      entryPoints:
+        - websecure
+      service: app
+      tls: {}
+
+  services:
+    app:
+      loadBalancer:
+        servers:
+          - url: "http://127.0.0.1:3000"
+```
+With this configuration, Traefik terminates TLS and serves your app over HTTP/2.
+
+## HTTP/3 (QUIC) Support
+While Early Hints (103 responses) are officially part of HTTP/2 and newer, many reverse proxies also support HTTP/3 (QUIC).
+
+Nginx: Requires a recent build with QUIC/HTTP3 patches.
+Traefik: Supports HTTP/3 via its entryPoint configuration.
+
+Enabling HTTP/3 is optional but can provide lower latency and improved performance for clients that support it. If you enable HTTP/3, your Early Hints responses will still work as expected.
+
+For more details, see the official documentation:
+
+- [Nginx HTTP/2 Module](https://nginx.org/en/docs/http/ngx_http_v2_module.html)  
+- [Nginx QUIC / HTTP/3](https://nginx.org/en/docs/quic.html)  
+- [Traefik HTTP/3](https://doc.traefik.io/traefik/reference/install-configuration/entrypoints/#http3)