Get a session element in the view with Laravel

Question

I'm trying to implement Google Recaptcha in my user registration form.

Controller

protected function validator(array $data)
{
    return Validator::make($data, [
        'name' => ['required', 'string', 'max:255'],
        'surname' => ['required', 'string', 'max:255'],
        'nickname' => ['required', 'string', 'max:255', 'min:5', 'unique:users'],
        'email' => ['required', 'string', 'email', 'max:255', 'unique:users'],
        'password' => ['required', 'string', 'min:8', 'confirmed'],
        'g-recaptcha-response' => function ($attribute, $value, $fail) {
            $secretKey = config('services.recaptcha.secret');
            $response = $value;
            $userIP = $_SERVER['REMOTE_ADDR'];
            $url = "https://www.google.com/recaptcha/api/siteverify?secret=$secretKey&response=$response&remoteip=$userIP";
            $response = file_get_contents($url);
            $response = json_decode($response);
            
            if (!$response->success) {
                Session::flash('errorCaptcha', 'Per favore controlla il reCaptcha!');
                $fail($attribute . 'Google reCaptcha fallito!');
            }
        }
    ]);
}

Instead, the code in the view should show an error message if the user does not confirm the Recaptcha.

Blade

@if(Session::has('errorCaptcha'))
    <span class="invalid-feedback" role="alert">
        <strong>{{ Session::get('errorCaptcha') }}</strong>
    </span>
@endif

In the controller I run:

dd(session::get('errorCaptcha'))

I get the value in the controller but not in the view. Can anyone help me, please?