Joom Donation Error: 0 The PHP cURL extension must be installed to use Guzzle.

I just reactivated Authorize.net in our Joom Donation Donation page.
When I went to test it, by donating with my own credit card, I got this error:

Error: 0 The PHP cURL extension must be installed to use Guzzle.

I checked my server and cURL is active. I even tried to obtain a new transaction key from authorize.net but that didn't help.

I have no idea what "Guzzle" is, probably a library of some sort, but I made sure cURL was active on my server.

What could be going wrong?

PS: when I tried to enter a ticket I got blocked by some kind of security bot. I'll try again but I figured I'd get on the forum as this is very time sensitive.

Hi,
Actually, the Authorize.net payment gateway needs cURL need to be enabled to work properly.
In your case, you can find solution through this link: mydaytodaywork.blogspot.com/2016/08/the-...tension-must-be.html to find solution to enable cURL.
If it isn't success, you can contact with Hosting admin to enable cURL library for you.
Thanks
Dam