Global Menu on Manjaro XFCE.sh

pamac install appmenu-gtk-module vala-panel-appmenu-registrar libdbusmenu-glib libdbusmenu-gtk2 libdbusmenu-gtk3
pamac build vala-panel-appmenu-xfce-git xfce4-windowck-plugin xfce4-panel-profiles

# If vala-panel-appmenu-xfce-git crashes compiling, you can replace it with the version on Manjaro community repository:
# `pamac install vala-panel-appmenu-xfce`


xfconf-query -c xsettings -p /Gtk/ShellShowsMenubar -n -t bool -s true
xfconf-query -c xsettings -p /Gtk/ShellShowsAppmenu -n -t bool -s true
xfconf-query -c xfwm4 -p /general/button_layout -s "CHM|O"
xfconf-query -c xfwm4 -p /general/titleless_maximize -s true
xfconf-query -c xsettings -p /Gtk/Modules -n -t string -s "appmenu-gtk-module"

reboot

# To revert to original
xfconf-query -c xsettings -p /Gtk/ShellShowsMenubar -n -t bool -s false
xfconf-query -c xsettings -p /Gtk/ShellShowsAppmenu -n -t bool -s false
xfconf-query -c xfwm4 -p /general/button_layout -s "O|HMC"
xfconf-query -c xfwm4 -p /general/titleless_maximize -s false
xfconf-query -c xsettings -r -p /Gtk/Modules

I ran added the following package before installing and the dependency problem was solved:
pamac install gobject-introspection