Directory structure
If you are not familiar with the FreeBSD filesystem layout, I recommend you read this manual page: https://www.freebsd.org/cgi/man.cgi?query=hier&sektion=7. You may find some stimulating directory descriptions on this page, so it is worth reading.
On OPNsense, the most relevant directories reside on the /usr/local
path:
root@bluebox:/usr/local # ls Makefile libdata openssl share bin etc libexec opnsense var cloudfence include &...