php curl SSL certificate

getting this error when running CURL files/download from PHP

Error:SSL certificate problem, verify that the CA cert is OK. Details:
error:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify
failed

I was able to go here and get a certificate that enabled cURL to work in
windows.
https://curl.haxx.se/docs/caextract.html

Is there a folder to copy that certificate to in the IFS to enable cURL to
work from PHP?

function dropbox_GetDebug( )
{
// Generated by curl-to-PHP: http://incarnate.github.io/curl-to-php/
$ch = curl_init();

curl_setopt($ch, CURLOPT_URL, "
https://content.dropboxapi.com/2/files/download";);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_POST, 1);

$headers = array();
$headers[] = "Authorization: Bearer xxxxxxxxxxxxxxxxxxxxx";
$headers[] = "Dropbox-Api-Arg: {\"path\": \"/test_upload.txt\"}";
curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);

$result = curl_exec($ch);
if (curl_errno($ch)) {
echo 'Error:' . curl_error($ch);
}
curl_close ($ch);

return $result ;
}



thanks,