Hi Trong,
I believe that would be possible. But first, if you don’t want that message to be displayed on the checkout, maybe it’s a better idea to find out why it’s happening. For example, if this option is enabled you could try to disable:
– WooCommerce > Settings > Products > Add to cart behaviour > Redirect to the cart page after successful addition
Even so, if you want to use the plugin to remove that message, you can go to the section “Messages” and add the “course is added cart…” message to the “Original HTML Content” option, and enable the Remove message option. But the problem is the message is going to be removed completely, not only on checkout.
Let me know if it helps