I solved problem, changed a bit localisation of files(removed vendor) and it works. Last thing I need to do is adding attachment.
I added line, but still can send only mail without attachment. Aslo created folder upload on catalog with my project.
$file_name = $_POST['file'];
$mail->addAttachment("uploads/".$file_name);
My new working code:
   ```php 
<?php 
    
ini_set('display_errors', '1');
ini_set('display_startup_errors', '1');
error_reporting(E_ALL);
 
use PHPMailer\PHPMailer\PHPMailer;
use PHPMailer\PHPMailer\SMTP;
use PHPMailer\PHPMailer\Exception;
    
require 'autoload.php';
       
$nameU = $_POST['name'];
$email = $_POST['email'];
$content = $_POST['message'];
$phoneU = $_POST['phone'];
$file_name = $_POST['file'];
$mail = new PHPMailer; //From email address and name 
$mail->From = $email ; 
$mail->FromName = $nameU; //To address and name 
$mail->addAddress("jaroslaw.mor@gmail.com", "Vomo");//Recipient name is optional
$mail->isHTML(true); 
$mail->Subject = "Zapytanie ze strony www"; 
$mail->Body = "Telefon:$phoneU<br>$content";
$mail->AltBody = "Telefon:$phoneU\n$content"; 
$mail->addAttachment("uploads/".$file_name);
if(!$mail->send()) 
{
    echo "Mailer Error: " . $mail->ErrorInfo;
} 
else 
{
    echo "Message has been sent successfully";
}```
