Redirect after submit comment?

I hope someone can help with this, I’ve tried all day to get this working with no luck. I’m trying to have the submit button for the comments box redirect the user to a “thank you” confirmation type page. I’ve tried the following code in the input with no luck:

<p class=”add_comment”>
<input type=”hidden” name=”comment_post_ID” value=”<?php echo $id; ?>” />
<input type=”submit” name=”submit” value=”Add Comment”>
<input type=”hidden” name=”redirect_to” value=”index.php” />
</p>
<?php do_action(‘comment_form’, $post->ID); ?>

When I add the redirect line, it only redirects, and doesn’t post the comment anymore. I’ve looked all over, and I can’t get it to work. I found this link:

https://www.theblog.ca/wordpress-redirect-comment

And thought that I might have some luck using that plugin, but I’m not sure if I put the code for the message display in the right place since I haven’t had any luck with that either. Any help would be greatly appreciated, I’m about to throw my laptop on the ground. You can find my site here.