lf-araujo I haven't customized them, but you can edit keyboard combos with labwc by editing labwc's config file. The default file is located at $HOME/.config/labwc/rc.xml. Once this PR is merged and synced, though, the config for Xfce will move to $HOME/.config/xfce4/labwc/rc.xml, and will contain Xfce-specific defaults.
As an example, to open Alacritty with Ctrl+Alt+t:
<keyboard>
<keybind key="C-A-t"><action name="Execute" command="alacritty" /></keybind>
</keyboard>