Deploying the Securly SSL Decryption Certificate to Firefox can be difficult because Firefox does not respect the Operating System settings and there is no native way to centrally manage Firefox. This article describes how Firefox can be configured to trust the Windows certificate store which makes certificate management much easier.

Note that the following guidance is provided 'as is' and cannot be directly supported by Securly beyond what is outlined in this article.

Distributing Firefox Preferences Files via Group Policy

Group policy can be used to distribute the above files.

Note that this process requires Firefox to be installed to the default location on the client's computer.

Add the files ‘securly.cfg' and 'local-settings.js' to a network share. Ensure that the share has read permissions for 'Domain Computers'.
Create/Edit a group policy in the "Group Policy Management".
Edit the settings in 'Computer Configuration > Preferences > Windows Settings > Files'.
Right-click and select 'New File'.
Point the 'Source File' to securly.cfg on the Network Share.
Point out the 'Destination' file to be C:\Program Files\Mozilla Firefox\securly.cfg and 'Apply'.
Repeat the above step to copy the same file to C:\Program Files (x86)\Mozilla Firefox\securly.cfg
Repeat these steps to copy 'local-settings.js' to C:\Program Files\Mozilla Firefox\defaults\pref\local-settings.js
Repeat these steps to copy 'local-settings.js' to C:\Program Files (x86)\Mozilla Firefox\defaults\pref\local-settings.js

Enabling Firefox preferences on MAC

How to manage Securly SSL certificate for Firefox with GPO