Unable to create an org policy to deny the creation of all external load balancers

[mountaincode2]

I want to create an org policy to deny the creation of all external load balancers:

I am referring to the following documentation:

https://cloud.google.com/load-balancing/docs/org-policy-constraints

• Deny all external load balancers

  {
  "constraint": "constraints/compute.restrictLoadBalancerCreationForTypes",
  "listPolicy": {
    "deniedValues": [
      "in:EXTERNAL"
    ]
  }
  }

The following is my workflow:

1. Created the following org policy in my project: `constraints/compute.restrictLoadBalancerCreationForTypes` using the instructions in the following: https://cloud.google.com/resource-manager/docs/organization-policy/creating-managing-policies#boolea...

2. When i try to create a load balancer, i get the following, which is expected:

Constraint constraints/compute.restrictLoadBalancerCreationForTypes violated for projects/org-policy-12345. Forwarding Rule projects/xxxxxx/global/forwardingRules/frontend-5 of type GLOBAL_EXTERNAL_MANAGED_HTTP_HTTPS is not allowed.

But now i want to update this org policy to only deny creation of external load balancers:

3. In the "Organization Policies" page in the Google Cloud Console, i select the constraint `constraints/compute.restrictLoadBalancerCreationForTypes`  from the list and clicked `Manage Policy`.

4. I then went to Add a rule > Add condition > Condition Editor, and entered the following, but i get an error:

What am i missing in my understanding please?