Here's a version that doesn't need a server. Just save as an HTML file and open it in a browser (either localhost or on a fileserver somewhere).

    <!DOCTYPE html>
    <html lang="en">
    <head>
        <meta charset="UTF-8">
        <meta name="viewport" content="width=device-width, initial-scale=1.0">
        <title>Note App</title>
        <style>
            body { font-family: Arial, sans-serif; margin: 0; padding: 20px; }
            textarea { width: 100%; height: 80vh; padding: 10px; font-size: 16px; border: 1px solid #ccc; border-radius: 5px; box-sizing: border-box; }
        </style>
    </head>
    <body>
        <textarea id="textarea" placeholder="Write your notes here..." autofocus></textarea>
        <script>
            document.addEventListener('DOMContentLoaded', function() {
                const textarea = document.getElementById('textarea');
                const loadValue = () => {
                    const hash = window.location.hash;
                    try {
                        const value = hash ? decodeURIComponent(atob(hash.substring(1))) : '';
                        textarea.value = value;
                        textarea.selectionStart = value.length;
                    } catch (e) {
                        console.error('Error decoding hash:', e);
                        textarea.value = '';
                    }
                };
                const storeValue = (value) => window.location.hash = '#' + btoa(encodeURIComponent(value));
                textarea.addEventListener('input', () => storeValue(textarea.value), false);
                window.addEventListener('hashchange', loadValue);
                loadValue();
            });
        </script>
    </body>
    </html>

It doesn't. Registering a dedicated .com domain is an overkill for this as well.