based on this documentation https://wiki.archlinux.org/title/Xsettingsd
I try to modify the modify icon theme from breeze to papirus-icon-theme at Net/IconThemeName
here the config location ~/.config/xsettingsd/xsettingsd.conf
Gdk/UnscaledDPI 122880
Gdk/WindowScalingFactor 1
Gtk/EnableAnimations 1
Gtk/DecorationLayout "icon:minimize,maximize,close"
Net/ThemeName "Breeze"
Gtk/PrimaryButtonWarpsSlider 1
Gtk/ToolbarStyle 3
Gtk/MenuImages 1
Gtk/ButtonImages 1
Gtk/CursorThemeSize 30
Gtk/CursorThemeName "breeze_cursors"
Net/SoundThemeName "ocean"
Net/IconThemeName "papirus-icon-theme"
Gtk/FontName "Noto Sans, 10"