This is a bit off topic here, but I read briefly the documentation and at page 8 it describes that in order to work it requires that your webserver has the php_curl extension enabled.
The documentation takes for granted that the web server you are using is Apache and that you have access to the php.ini file, but that depends on your infrastructure provider/hosting. Many hosting enable this extension by default.
I'd suggest you to check the list of extension enabled, by using the phpinfo() function first. If php_curl it is not enabled, check your hosting documentation and/or contact the support to ask to enable this extension.
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