Buy botton doesn’t appear – Woocommerce

Hi,
I have been selling online course for more than 6 months, but now
the buy button in my checkout has disappeared, so my clients can’t buy my course.
I’m using the checkout block in the checkout page (not the code).
I’m also using this Theme – https://themeforest.net/item/efor-coaching-online-courses-wordpress-theme/22838389.

Can somebody help me??

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