Merge pull request #52512 from edburns/edburns-MSFT-appGatewayKeyVault

On branch edburns-MSFT-appGatewayKeyVault https://stackoverflow.micro…

Author: ktoliver

articles/application-gateway/key-vault-certs.md

@@ -42,7 +42,10 @@ Application Gateway integration with Key Vault requires a three-step configurati
 
 1. **Configure your key vault**
 
-   You then either import an existing certificate or create a new one in your key vault. The certificate will be used by applications that run through the application gateway. In this step, you can also use a key vault secret that's stored as a password-less, base 64-encoded PFX file. We recommend using a certificate type because of the autorenewal capability that's available with certificate type objects in the key vault. After you've created a certificate or a secret, you define access policies in the key vault to allow the identity to be granted *get* access to the secret.
+   You then either import an existing certificate or create a new one in your key vault. The certificate will be used by applications that run through the application gateway. In this step, you can also use a key vault secret that's stored as a password-less, base-64 encoded PFX file. We recommend using a certificate type because of the autorenewal capability that's available with certificate type objects in the key vault. After you've created a certificate or a secret, you define access policies in the key vault to allow the identity to be granted *get* access to the secret.
+   
+   > [!NOTE]
+   > If you deploy the application gateway via an ARM template, either by using the Azure CLI or PowerShell, or via an Azure Application deployed from the Azure portal, the SSL certificate that's stored in the key vault as a base-64-encoded PFX file **must be passwordless**. Also, you must complete the steps in [Use Azure Key Vault to pass secure parameter value during deployment](../azure-resource-manager/templates/key-vault-parameter.md). It's particularly important to set `enabledForTemplateDeployment` to `true`.
 
 1. **Configure the application gateway**