Keyboard Mapping for Raspbian


I am running Raspbian Bullseye on my Pi-Top [1]. I remember that I mapped they Function Keys on the previous build but I cannot find any details on this after searching the web for over 2 hours I gave up:
Volume Down
Volume Up
Dim Screen
Bright Screen
File Manager

Does anyone have the details about mapping these keys in Raspbian?

Thanks in advance!

Ok, strange, somehow they started working. It seems it added it by it self after a reboot.
But I did finally find what needs to be added to /etc/xdg/openbox/lxde-pi-rc.xml:

<keybind key="0xC6">
  <action name="Execute">
    <command>sh -c "if test -e /usr/bin/pt-brightness; then /usr/bin/pt-brightness -d; fi"</command>
<keybind key="0xC7">
  <action name="Execute">
    <command>sh -c "if test -e /usr/bin/pt-brightness; then /usr/bin/pt-brightness -i; fi"</command>