Compilation failed

[AozoraDev]

  CC       libsoundmenu_la-soundmenu-panel-plugin.lo
In file included from soundmenu-dialogs.h:23,
                 from soundmenu-panel-plugin.c:24:
soundmenu-panel-plugin.h:36:10: fatal error: libxfce4panel/xfce-hvbox.h: No such file or directory
   36 | #include <libxfce4panel/xfce-hvbox.h>
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
compilation terminated.
make[2]: *** [Makefile:671: libsoundmenu_la-soundmenu-panel-plugin.lo] Error 1

Looks like this plugin still using GTK2.
I would also love if this plugin was updated.