missing header files in /usr/include/libzfs

I'm using ubuntu focal 20.04.
the problem is with zfs header sources in ubuntu in /usr/include/libzfs/.

in zfs source code there is a header file: "zfs/lib/libzfs/libzfs_impl.h" and there are includes to other .h files:

#include <sys/fs/zfs.h>
#include <sys/nvpair.h>
#include <sys/dmu.h>
#include <sys/zfs_ioctl.h> -> * problematic include
#include <regex.h>

#include <libuutil.h>
#include <libzfs.h>
#include <libshare.h>
#include <libzfs_core.h>

link:
https://github.com/openzfs/zfs/blob/master/lib/libzfs/libzfs_impl.h

seems like all the headers exist in ubuntu focal in /usr/include/libzfs/ but
the .h file that don't exist in ubuntu focal is /usr/include/libzfs/sys/zfs_ioctl.h
This bug prevents me from generating code with header files with its dependencies because its dependencies not exist.