I am using EB Garamond for my font, but there's a few places I need some special characters, like a checkmark symbol, so I'm trying to set FreeSerif as a fallback.

\definefallbackfamily[main] [serif] [file:/home/joel/.fonts/FreeSerif.otf] [range=dingbats, force=yes]
\definefallbackfamily[main] [sans] [file:/home/joel/.fonts/FreeSerif.otf] [range=dingbats, force=yes]

\starttypescript[serif]                            [garamond]
    \definefontsynonym[Serif]                    [file:/home/joel/.fonts/EBGaramond-Regular.otf]
    \definefontsynonym[SerifBold]                [file:/home/joel/.fonts/EBGaramond-Bold.otf]
    \definefontsynonym[SerifItalic]                [file:/home/joel/.fonts/EBGaramond-Italic.otf]
    \definefontsynonym[SerifBoldItalic]            [file:/home/joel/.fonts/EBGaramond-BoldItalic.otf]
    \definefontsynonym[SerifCaps]                [file:/home/joel/.fonts/EBGaramond12-AllSC.otf]
\stoptypescript
%
\starttypescript[sans]                            [garamond]
    \definefontsynonym[Sans]                    [file:/home/joel/.fonts/OptimaLTStd-Bold.otf]
    \definefontsynonym[SansBold]                [file:/home/joel/.fonts/OptimaLTStd.otf]
    \definefontsynonym[SansItalic]                [file:/home/joel/.fonts/EBGaramond-Italic.otf]
    \definefontsynonym[SansBoldItalic]            [file:/home/joel/.fonts/LeMurmure-Regular.otf]
    \definefontsynonym[SansCaps]                [file:/home/joel/.fonts/EBGaramond12-AllSC.otf]
\stoptypescript
%
\starttypescript[garamond]
    \definetypeface[garamond]                    [rm][serif][garamond][default]
    \definetypeface[garamond]                    [ss][sans][garamond][default]
    \definetypeface[garamond]                    [mm][math][math][default]
\stoptypescript
%


I've looked through many handbooks and old questions on-line and tried many configurations. It appears the way to define the fallback has changed many times over the years, and none I've tried works. I've confirmed I can make ConTeXt use my font "FreeSerif.otf", but I can't get it to appear as a fallback. Basically if the character can't be found in EB Garamond, I hope it will use FreeSerif.otf, but generally, I'm just using it for a couple special symbols.
How do I correct his so it properly displays the symbols from FreeSerif.otf?
--Joel