codes.html

<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <script src="./codes.js" type="javascript"></script>
    <title>Add code</title>
</head>
<body>
    <div id="main">
        <form method="post" onsubmit="addcode(event)" id="form_1">
            <div>
                <label class="label" for="codes">Codes (if more than one, separate them by space like "ASDEFR ASDEFRG")</label>
                <div class="control has-icons-left has-icons-right">
                    <input class="input is-primary" id="codes" name="codes" type="text" required value />
                    <span class="icon is-small is-left"><i aria-hidden="true" class="fas fa-user"></i></span>
                    <span class="icon is-small is-right"><i aria-hidden="true" class="fas fa-check"></i></span>
                </div>
                <br/>
                <div>
                    <button type="submit" onsubmit="addcode(event)" class="button is-success">Submit</button>
                </div>
            </div>
        </form>
    </div>
</body>
</html>