Here is a sample code using PHP to send a push notification to your mobile application using the OneSignal API. Create a free account on https://onesignal.com/ and get your OneSignal AppID and OneSignal RestID keys.
I use the below PHP code in a web app to send OneSignal push notifications to Xamarin Forms apps using the OneSignal Nuget https://www.nuget.org/packages/Com.OneSignal/
You can use this code in any PHP page for use in web form post, cron job, web api, etc…
See my C# example here
function OneSignalSender($userid, $message) { $onesignalappid = 'your-onesignalappid'; $onesignalrestapikey = 'your-onesignalrestapikey'; //if using filters to a tag with a userid $filters = array( array("field" => "tag", "key" => "userid", "relation" => "=", "value" => $userid) ); $subtitle = array( "en" => 'the title'; //Title for ios 10 or higher ); $headings = array( "en" => 'title';// Title' ); $content = array( "en" => $message//this is the message ); $fields = array( 'app_id' => $onesignalappid, //'included_segments' => array('All'), //uncomment if using segments //'filters' => $filters, //uncomment if using filters 'large_icon' => "ic_launcher_round.png", 'contents' => $content, 'headings' => $headings, 'subtitle' => $subtitle ); $fields = json_encode($fields); $ch = curl_init(); curl_setopt($ch, CURLOPT_URL, "https://onesignal.com/api/v1/notifications"); curl_setopt($ch, CURLOPT_HTTPHEADER, array ( 'Content-Type: application/json; charset=utf-8', 'Authorization: Basic ' . $onesignalrestapikey ) ); curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE); curl_setopt($ch, CURLOPT_HEADER, FALSE); curl_setopt($ch, CURLOPT_POST, TRUE); curl_setopt($ch, CURLOPT_POSTFIELDS, $fields); curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE); $response = curl_exec($ch); curl_close($ch); return $response; }