Can’t purchase the Extension plugin

I’m trying to purchase the extension plugin.
First when I clicked on visa icon it opened the payment details form but after I fill all Visa card data and personal detail and click on continue, it just get stuck showing a spinning icon and nothing happens, I already tried twice in Firefox and MS-edge browsers without luck, third time I clicked on visa icon it it opened paypal ( pay by credit or debit card) option, I have no idea why, but I went for it and entered all card details, but it gave me errors and payment failed.
What should I do?
Kindly contact me we need the extension plugin urgently

Thank you

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