Where freebsd's firefox port search firefox.js?

[C. L. Martinez]

Hi all,

 I am trying to lock some preferences for Firefox browser for all users. According to Mozilla's docs, a firefox.js needs to exists. I have tried to put in on /usr/local/etc/firefox, but no lockPref are applied.

 Where do I need to setup/install firefox.js file under FreeBSD? I am using FreeBSD 11 and firefox-53.0_2,1 version.

Thanks.

-- 
Greetings,
C. L. Martinez