Request failed with status code: 401

I have fill all of the values, I want to know what's wrong with these code.
OS: Windows 11
rustc: 1.70.0 (90c541806 2023-05-31)
git2: 0.17.2

My code:

fn push_repo() -> Result<(), git2::Error> {
    let repo = Repository::open("cache/repo")?; 

    let mut remote = repo.find_remote("origin")?;

    remote.connect_auth(Direction::Push, Some(create_callbacks()), None).unwrap();
    repo.remote_add_push("origin", "refs/heads/temp:refs/heads/temp").unwrap();
    let mut push_options = PushOptions::default();
    let callbacks = create_callbacks();
    push_options.remote_callbacks(callbacks);
    remote.push(&["refs/heads/temp:refs/heads/temp"], Some(&mut push_options)).unwrap();

    std::mem::drop(remote);

    Ok(())
}
fn create_callbacks<'a>() -> RemoteCallbacks<'a>{
    let mut callbacks = RemoteCallbacks::new();
    callbacks.credentials(|_url, username_from_url, _allowed_types| {
        // Use the username from the url or a default one
        let username = username_from_url.unwrap_or("git");
        Cred::ssh_key(
            username,
            Some(std::path::Path::new("ssh_key/pushzig_rsa.pub")),
            std::path::Path::new("ssh_key/pushzig_rsa"),
            None,
        )
    });
    callbacks
}

Error:

thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: Error { code: -1, klass: 34, message: "request failed with status code: 401" }', src\main.rs:261:74
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
error: process didn't exit successfully: `target\debug\zos-index-generator.exe new` (exit code: 101)

Start at src/main.rs:261 and inspect push_repo and create_callbacks, especially the SSH credential setup and the remote.push call. Reproduce the 401 with the stated Rust and git2 versions, then determine whether the failure is caused by the example's credentials or by git2-rs; document a confirmed cause and reproduction details.