Before I answer you further, please let us know if you purchased the extension before or not. We need to verify the order before providing further support, sorry
Hi Tuan, yes we purchased it. However, not to worry, I see the TOTAL field is working automatically. I think this is OK, though setting up quantity fields would be a little better.
Yes. Please go to
joomdonation.com/support-tickets.html
submit a support ticket let us know the email you used to purchase the product to verify the order so that we can continue providing future support requests
