WebPush-Server

uses
  sgcWebSocket, sgcWebSocket_Server_APIs;

var
  Server: TsgcWebSocketHTTPServer;
  WebPush: TsgcWSAPIServer_WebPush;
begin
  Server := TsgcWebSocketHTTPServer.Create(nil);
  Server.Port := 8443;
  Server.SSL  := True;

  WebPush := TsgcWSAPIServer_WebPush.Create(nil);
  WebPush.Server := Server;
  WebPush.VAPID.Subject := 'mailto:admin@example.com';
  WebPush.VAPID.PrivateKey.LoadFromFile('vapid-priv.pem');
  WebPush.VAPID.PublicKey.LoadFromFile ('vapid-pub.pem');

  Server.Active := True;

  // later, when you have a subscription record
  WebPush.SendNotification(
    'https://fcm.googleapis.com/wp/...', // endpoint
    'p256dh-public-key', // from PushSubscription.getKey(p256dh)
    'auth-secret', // from PushSubscription.getKey(auth)
    '{"title":"Hello","body":"Notification body"}');
end;