add note about enabling feature for your team

Author: alicenstar

docs/vendor/enterprise-portal-configure.mdx

@@ -125,7 +125,7 @@ To customize the pre- and post-install instructions for your application:
 ## Customize Channel-Specific Install Instructions (Alpha) {#customize-channel-install-instructions}
 
 :::note
-This feature is in Alpha and subject to change.
+Custom install instructions are Alpha and subject to change. To access this feature, a feature flag must be enabled for your team. For more information, reach out to your Replicated account representative.
 :::
 
 By default, the installation instructions available in the Enterprise Portal are automatically generated based on the install types and options enabled in the customer's license. These default installation instructions are the same across all release channels. For more information about managing the install types and options, see [Manage Install Types for a License](/vendor/licenses-install-types).