Add Placeholder to Comment Form

placeholdercommentform.php

function my_update_comment_field( $comment_field ) {

  $comment_field =
    '<p class="comment-form-comment">
            <label for="comment">' . __( "Comment", "text-domain" ) . '</label>
            <textarea required id="comment" name="comment" placeholder="' . esc_attr__( "Enter comment here...", "text-domain" ) . '" cols="45" rows="8" aria-required="true"></textarea>
        </p>';

  return $comment_field;
}
add_filter( 'comment_form_field_comment', 'my_update_comment_field' );