Checkbox bug

Hello,

My site is coming soon then I will create to you an access if you need it.

I bought your pro plugin on wooextend.com and I have a problem on the checkbox on the cart page.

I can’t select the free gift, the popup is working but when I click on the item nothing is happening.
Do you know why ? If not contact me at [email protected] please.
I will give you an access to the website.

Thank you in advance.

Regards.

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