For anyone who has used or plans to use the onesignal node SDK (@onesignal/node-onesignal)
After a week of developing onesignal custom modules via the SDK I contacted onesignal support regarding same issues with the SDK reference to be told that the SDK should NOT be used at present as they are reworking it, moving from players (now depreciated) to users (currently incomplete)
They advise all interaction via API calls at present