In the code I wrote below, when I click on the submit button, it downloads the iletişim.php file, it does nothing else, I don't know why.
PHP
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <link rel="stylesheet" type="text/css" href="iletişim.css">
</head>
<body>
    <?php
    if(!empty ($_POST["submit"])){
        $Username = $_POST["Username"];
        $Useremail = $_POST["Useremail"];
        $userMessage = $_POST["userMessage"];
        $toEmail = $_POST["efealiazad@gmail.com"]
        
        $mailHeaders = "Name:" . $Username .
        "\r\n Email:" . $Useremail .
        "\r\n Message:" . $userMessage . "\r\n";
    }
    if(mail($toEmail, $Username, $mailHeaders)){
        $message = "Bilgileriniz Başarıyla Alındı"
    }
    ?>
        
        <form>
               <div class="araka slide-left">
                <div class="DS"><h3>Destek Sistemi</h3></div>
                <input type="text" id="name" name="Username" class="contact-form-text" placeholder="Adınız/soyadınız" required>
                <input type="email" id="email" name="Useremail" class="contact-form-text" placeholder="E-Posta Adresiniz" required>
                <textarea name="userMessage" id="" cols="30" rows="10" class="contact-form-text" placeholder="Sorununuz nedir kısaca özetleyin" required></textarea>
                <input type="submit" value="submit" name="Gönder" class="contact-form-text-btn submit">
        </form> 
       
</body>
</html>
HTML
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <link rel="stylesheet" href="iletişim.css">
    <title>İletişim Bilgileri|Ad</title>
    <script src="https://code.jquery.com/jquery-3.4.1.js"></script>
</head>
<body>
    
    <div class="header">
        <nav>
            <div class="logo">
                <img src="images/logo.png">
                
            </div>
            <ul>
                <li><a href="index.html">ANA SAYFA</a></li>
                <li><a href="#">HESAP SATIN AL</a>
                    <ul class="submenu">
                        <li><a href="hesapsatınal.html#valorant" class="valorant">Valorant</a></li>
                        <li><a href="hesapsatınal.html#steam">Steam</a></li>
                    </ul>
                </li>
                <li><a href="iletişim.html">BİZE ULAŞIN</a></li>
                <li><a href="sözleşme.html">KULLANICI SÖZLEŞMESİ</a></li>
                <li><a href="FAQ.html">FAQ</a></li>
            </ul>
        </nav>
        <div class="sözls">
        <div class="skosul slide-left">  
        
    <form class="contact-form" action="iletişim.php">
           <div class="araka slide-left">
            <div class="DS"><h3>Destek Sistemi</h3></div>
            <input type="text" id="name" name="name" class="contact-form-text" placeholder="Adınız/soyadınız" required>
            <input type="email" id="email" name="email" class="contact-form-text" placeholder="E-Posta Adresiniz" required>
            <textarea name="" id="" cols="30" rows="10" class="contact-form-text" placeholder="Sorununuz nedir kısaca özetleyin" required></textarea>
            <input type="submit" id="" name="submit" class="contact-form-text-btn submit">
    </form> 
</div>
</body> 
</html>
I listened and wrote these php codes from a youtube tutorial video (except html) All I expect is that it doesn't download this php file and it doesn't run the content of the php code. Also, I don't have a domain name and hosting, could it be because of that?
