Hello, one more detail that might help.
It is not enough just to have CURL installed you must have an updated version.
I have already had problems with this, and checking the logs I found the following entry that caused the problem: cURL error 35: error: 14077410: SSL routines: SSL23_GET_SERVER_HELLO: sslv3 alert handshake failure
This "handshake" error in my case was for using an outdated version of CURL (7.21.0)
I requested to upgrade to my service provider for (7.52.0) and everything worked normally.
Here is the list of CURL versions
Https://curl.haxx.se/docs/releases.html
To check which version you have installed
By command line: $ curl -V
Or PHP with the famous phpinfo ();