Update customer-managed-keys-integration-service-environment.md

The change request comes from CSS ticket 2108100040004923.

Author: xuehongg

articles/logic-apps/customer-managed-keys-integration-service-environment.md

@@ -26,6 +26,8 @@ This topic shows how to set up and specify your own encryption key to use when y
 
 * You can specify a customer-managed key *only when you create your ISE*, not afterwards. You can't disable this key after your ISE is created. Currently, no support exists for rotating a customer-managed key for an ISE.
 
+* The keyvault containing the customer-managed key must be in the same region as the ISE's. 
+
 * To support customer-managed keys, your ISE requires that you enable either the [system-assigned or user-assigned managed identity](../active-directory/managed-identities-azure-resources/overview.md#managed-identity-types). This identity lets your ISE authenticate access to secured resources, such as virtual machines and other systems or services, that are in or connected to an Azure virtual network. That way, you don't have to sign in with your credentials.
 
 * Currently, to create an ISE that supports customer-managed keys and has either managed identity type enabled, you have to call the Logic Apps REST API by using an HTTPS PUT request.