My HTML page with a request form for chatGPT-3 gets no answer

API
10 
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <link rel="stylesheet" href="style.css">
    <title>ChatGPT Test</title>
</head>
<body>
 
<div>
    <h1>ChatGPT Test</h1>
    <div>
        <label for="userInput">Your message:</label>
        <input type="text" id="userInput">
        <button onclick="sendMessage()">Send</button>
    </div>
    <div id="chatDisplay"></div>
 
    <script src="script.js"></script>
</div>
 
</body>
</html>