Hi Kevin,
I went through this a few months ago and left some notes - not sure if they will be of any help to you ? OGS API notes
From a quick read of my notes, at a minimum you will need to use the REST authenticate call before you can push moves through the RT API; and you will need to use the login and config REST calls first to get the token that authenticate expects. But there may be more - my recollection is that the APIs can be fickle and fail in mysterious ways if you are missing some of the steps 