In FortiGate version 7.0.9, you don't "create" features in the sense of writing code, but you can or visibility-toggle built-in features that are hidden by default. Enabling Hidden Features (Feature Visibility)
https://docs.fortinet.com/product/fortigate/7.0.9If you are currently running 7.0.8 or older, the single biggest reason to upgrade to 7.0.9 is security. fortigate 7.0.9