You just made your filter for Forge mods. Now all you have to do is put file forge_filter you just downloaded in /plugins/FairPlayMinecraft/, set "use_filter_for_forge" to true and restart your server!
Step 2: Add .json file of the version (client)
For example if you want to add the official 1.10 version to the list, you will go to %appdata%/.minecraft/versions/1.10 and drag file 1.10.json here.
Drop .json here
FairPlayMinecraft Forge filter creator
Mods you have allowed:
There are no mods currently on the list! Click "Add mods to the list" to add a mod.
You are done adding mods to the list? Click the button to download the filter: