~/Library/LaunchAgents/MapContextKeyToF20.plist

MapContextKeyToF20.plist

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<!-- 
This remaps the Context Key (between the right hand Alt and Control on a normal keyboard) to the F20 key.

See https://apple.stackexchange.com/a/398797/264061

Source is stored in https://gist.github.com/alexhayes/be6257459eb7a2dbc1e5b2baaebdac90
-->
<plist version="1.0">
<dict>
    <key>Label</key>
    <string>com.local.KeyRemapping</string>
    <key>ProgramArguments</key>
    <array>
        <string>/usr/bin/hidutil</string>
        <string>property</string>
        <string>--set</string>
        <string>{"UserKeyMapping":[
            {
                "HIDKeyboardModifierMappingSrc": 0x700000065,
                "HIDKeyboardModifierMappingDst": 0x70000006F
            }
        ]}</string>
    </array>
    <key>RunAtLoad</key>
    <true/>
</dict>
</plist>