fix: Add OIDC notice to NIC Custom OIDC Docs (#1583)

Author: AlexFenlon

content/nic/tutorials/oidc-custom-configuration.md

@@ -13,6 +13,8 @@ This guide will walk through how to customize and configure this default impleme
 
 ## Prerequisites
 
+{{< call-out "note" >}}This guide only works with F5 NGINX Ingress Controller version 5.2.1 or below. Please make sure you are using a compatible version before proceeding.{{< /call-out >}}
+
 This guide assumes that you have an F5 NGINX Ingress Controller deployed. If not, please follow the installation steps using either the [Manifest]({{< ref "/nic/install/manifests.md" >}}) or [Helm]({{< ref "/nic/install/helm.md" >}}) approach.
 
 To customize the NGINX OpenID Connect Reference implementation, you will need to: