Pressing checkout doesn't do anything

Hi Guys,

I made a screencast, when i want to checkout, nothing happens, the page refresh itself but the same page loads in, please help to fix this.

Everything you told in this post i triple checked already
Enable Shopping Cart Mode | EShop Documentation (joomdonation.com)

Video to the issue:
od.lk/s/NjFfODI2Mjg1MzRf/Issue%20with%20...4-05-06_22-01-58.mp4

Dear Peter Horvath,

Thank you for submitting the question here too. I have already answered you via ticket system. The reason because products are out of stock so you can not checkout. To resolve the issue, please go to EShop -> System -> Configuration -> Option tab, at Stock Checkout, choose Yes, then Save the Configuration and test again.

Sincerely, Giang