CloudGuard WAF can be deployed as an add-on for NGINX or Kong, thus providing protection to any applications and APIs served by NGINX Reverse Proxy.
The CloudGuard WAF Nano Agent attaches itself to the traffic being proxied by the Proxy Server or API server.
If the server serves applications locally, and does not serve as a proxy between an exposed domain and an internal one - the Nano Agent can still inspect the traffic if you change the port for the local applications to a higher port, and add a proxy rule between the exposed listening domain and port, to the same local machine at a higher port.