How to add An HTML form where the field's text direction will be submitted

<!DOCTYPE html> <html> <body> <h1>The textarea dirname attribute</h1> <form action="/action_page.php"> Text:<br> <textarea name="explanation"dirname="explanation.dir"></textarea> <input type="submit" value="Submit"> </form> <p>When the form is being submitted, the text direction of the textarea will also be submitted.</p> </body> </html>