Update Helm install command for NGINX Ingress

docs/en/get-started/pre-requirements.md

@@ -108,9 +108,11 @@ If you are using Helm, you can install NGINX Ingress using the following command
 ```cs
 helm repo add ingress-nginx https://kubernetes.github.io/ingress-nginx
 helm repo update
-helm upgrade --install --version=4.0.19 ingress-nginx ingress-nginx/ingress-nginx
+helm upgrade --install --version=4.0.19 ingress-nginx ingress-nginx/ingress-nginx --set controller.config.enable-underscores-in-headers="true"
 ```
 
+>  --set controller.config.enable-underscores-in-headers="true" is required to allow headers with underscores (e.g., `__tenant`) used by ABP framework.
+
 ### mkcert
 
 Use mkcert to generate trusted certificates for local development. You can install mkcert by following the [official mkcert installation guide](https://github.com/FiloSottile/mkcert#installation).