didn't can use "fdisk"!

[fuf <fuflono@gmail.com>]

Hello all.
I'm embarrassed because didn't can use "fdisk"!
I work as normal user, open the terminal, switch to "root" user but get:
root@debian:/sbin# fdisk  -l
bash: fdisk: command not found

whereas:
root@debian:/sbin# ls -al
.....
-rwxr-xr-x  1 root root    169520 Mar 23  2023 fdisk
....
why?
I reinstalled "util-linux" and "fdisk" by "Synaptic" but nothing varied.

What is matter?, give me any advice, please.
    --fuf