Woocommerce add to cart and redirect to Custom URL – Different for each link

So I am using a link on this page: https://www.revealio.com/make-brand-come-alive/ (yellow button).

The link is supposed to add the product to the cart and then send them to the next step in the sales funnel.

For the link URL I used:

https://www.revealio.com/help-creating-video?add-to-cart=4951
and

https://www.revealio.com/help-creating-video?add-to-cart=4951&quantity=1
Full link code is:

<a href="https://www.revealio.com/help-creating-video?add-to-cart=8877">YES! MAKE MY BRAND COME ALIVE!</a>
I found this code here: https://businessbloomer.com/woocommerce-custom-add-cart-urls-ultimate-guide/

If you need to see the cart (we are still redesigning these pages) you can go here in a seperate browser tab to see how it updates: https://www.revealio.com/cart/

The problem is that it is adding 2 products to my cart instead of 1.

How can I get this to just add one of my products to the cart and move on?

Here is something new I found out. If I just go directly to the link it only adds one product. If I click on the link in the page (https://www.revealio.com/make-brand-come-alive/) it adds 2 products. It does the same for a button or a text link.

The page I need help with: [log in to see the link]