Online PHP editor | output for 6sIS9

<?php $ch = curl_init(); $data = array("notification" => array('title' => 'abc', 'body' => 'cde', 'click_action' =>'http'), "to" => "/topics/default"); $data_string = json_encode($data); curl_setopt($ch, CURLOPT_URL,"https://fcm.googleapis.com/fcm/send"); curl_setopt($ch, CURLOPT_POST, 1); curl_setopt($ch, CURLOPT_POSTFIELDS, $data_string); curl_setopt($ch, CURLOPT_HTTPHEADER, array( 'Authorization:key=AAAA0oAC_b8: APA91bGl5xznSKY64_L1aHJwl0T9bt1DqJoZQDWCehJORJgiEFajcHnruT3lDbXPSYdAv7M6ni2iFgkHLQm3Bo9nU9d7gN-bofZ_Ve5ihBmc91tWEDviXDgRWodSgFq48ljG74zef9QI', 'Content-Type: application/json' )); // in real life you should use something like: // curl_setopt($ch, CURLOPT_POSTFIELDS, // http_build_query(array('postvar1' => 'value1'))); // receive server response ... curl_setopt($ch, CURLOPT_RETURNTRANSFER, true); $server_output = curl_exec ($ch); curl_close ($ch); print_r($server_output);