Probably not the same sort of token and probably nothing to do with your problem... but to create a bearer token for the interface I recently wrote I had to do:

s authstring=$TR($SYSTEM.Encryption.Base64Encode(headJSONstring,1),"=")_"."_$TR($SYSTEM.Encryption.Base64Encode(paylJSONstring,1),"=")_"."

s request.Authorization=" Bearer "_authstring

I had set the flag so that the Base64Encode didn't add CR/LF and strip padded ='s from the end and also the other end want a space before the word Bearer as well as after. I don't know if that's standard.

I also only used a standard Ens.BusinessOperation with an EnsLib.HTTP.OutboundAdapter to send my REST requests.