How to use AuthorizationPolicy's AUDIT log outside of GKE

There does not seem to be a lot of information around how to use the AUDIT feature of the AuthorizationPolicy object. Stackdriver is mentioned but there does not seem to be a way to run this without having a GKE account at the least or using a third-party vendor.

Is there any other way to have some tracing or trail of what connectivity is happening when using Authorization Policies?

I found this other dead thread but nothing really helpful on this board (and the invite link for the istio slack seems dead).

Thanks!

The full support for AUDIT logs currently is only available with StackDriver backend. But the infrastructure is general and can be extended to support any other backends.