subscriptions.cls

String Id = '<Your-Device Id>'; 
String endpoint = '<Your-public webservice URL>';
String littleBitEvent = 'amplitude:delta:ignite';
String accessToken = '<Device AccessToken>';
Http h = new Http();
HttpRequest req = new HttpRequest(); 
req.setMethod('POST'); 
req.setEndpoint('https://api-http.littlebitscloud.cc/subscriptions');
req.setHeader('Authorization','Bearer ' + accessToken);
req.setHeader('Accept', 'application/vnd.littlebits.v2+json');
req.setBody('publisher_id=' + Id + '&subscriber_id=' + endpoint);
HttpResponse response = h.send(req);