Update configure-site-to-site-vpn-gateway.md

Author: rvandenbedem

articles/azure-vmware/configure-site-to-site-vpn-gateway.md

@@ -4,7 +4,7 @@ description: Learn how to establish a VPN (IPsec IKEv1 and IKEv2) site-to-site t
 ms.topic: how-to
 ms.custom: contperf-fy22q1, engagement-fy23
 ms.service: azure-vmware
-ms.date: 12/06/2023
+ms.date: 12/15/2023
 ---
 
 # Configure a site-to-site VPN in vWAN for Azure VMware Solution
@@ -154,6 +154,8 @@ A virtual hub is a virtual network that is created and used by Virtual WAN. It's
    >[!IMPORTANT]
    >You must first have a private cloud created before you can patch the platform. 
 
+>[!IMPORTANT]
+   >You must also have an ExpressRoute Gateway configured as part of your Virtual WAN Hub. 
 
    [!INCLUDE [request-authorization-key](includes/request-authorization-key.md)]