al-authorizer>Define the external authorizer</h2><p>In order to use the <code>CUSTOM</code> action in the authorization policy, you must then define the external authorizer that is allowed to be
used in the mesh. This is currently defined in the <a href=https://github.com/istio/api/blob/a205c627e4b955302bbb77dd837c8548e89e6e64/mesh/v1alpha1/config.proto#L534>extension provider</a>
in the mesh config.</p><p>Currently, the only supported extension provider type is the <a href=https://www.envoyproxy.io/docs/en