Configures the external URL policies. URL drilldowns respect the global External URL service, which you can use to deny or allow external URLs. By default all external URLs are allowed.

For example, to allow only external URLs to the example.com domain with the https scheme, except for the danger.example.com sub-domain, which is denied even when https scheme is used:

externalUrl.policy:
  - allow: false
    host: danger.example.com
  - allow: true
    host: example.com
    protocol: https