$curl = curl_init( 'https://httpbin.org/post' );
curl_setopt( $curl, CURLOPT_POST, true );
curl_setopt( $curl, CURLOPT_POSTFIELDS, array( 'field1' => 'some data', 'field2' => 'some more data' ) );
curl_setopt( $curl, CURLOPT_RETURNTRANSFER, true );
$response = curl_exec( $curl );
curl_close( $curl );