Home manager installation failed

Hi,
I add home manager configuration to the configuration.nix. Unfortunately, after reboot, I did not get the home-manager command.

$ diff /etc/nixos/configuration.nix.orginal /etc/nixos/configuration.nix.home-manager 
5c5,12
< { config, pkgs, ... }:
---
> { config, pkgs, lib, ... }: 
> 
> let
>   home-manager = builtins.fetchTarball https://github.com/nix-community/home-manager/archive/release-25.05.tar.gz;
>   
>   # Define your system and Home Manager state version here
>   myNixOSVersion = "25.05";
> in
10a18
>       (import "${home-manager}/nixos")
11a20,31
> 
>   # Configure Home Manager for your user
>   users.users.eve.isNormalUser = true;
>   home-manager.users.michal = { pkgs, ... }: {
>     # Add packages you want installed for this user
>     # home.packages = [ pkgs.atool pkgs.httpie ];
>     programs.bash.enable = true;
>   
>     # The state version is required and should stay at the version you
>     # originally installed.
>     home.stateVersion = "25.05";
>   };

$ sudo nano /etc/nixos/configuration.nix
$ sudo nixos-rebuild dry-build
$ sudo nixos-rebuild switch

What did I do wrong?

This gives you the home-manager functionality for your user, but not the command. Whenever you rebuild your system, it will also take care of the home-manager stuff.
If you additionally want the home-manager command, you have to list it in the installed packages.

Thank you, How can I immediately see the effect off changing dotfiles in configuratation.nix rather than after rebooting?

sudo nixos-rebuild switch should have an immediate effect.

Thank you, it works.