JSON sent:
{"app_id":"b49bd148-ce3f-4fa2-9fb5-361d91d2a4e0","include_player_ids":["f271d306-58f8-4db8-af7d-d1c43abcba6d"],"data":{"foo":"bar"},"contents":{"en":"Nutrifiks Order Delivery System Notification Sended By Ahsan"}}

JSON received:
{"allresponses":"{\"errors\": [\"Access denied.  Please include an 'Authorization: ...' header with a valid API key (https:\/\/documentation.onesignal.com\/docs\/en\/keys-and-ids#api-keys).\"]}\n"}