JSONString in V3 API POST

JSONString in V3 API POST

Hi

Can I just query exactly what the body of a POST in the V3 API should be? The docs seem to indicate the body itself should be JSONString='<some json>' but surely this is not the case? Surely the body should simply be json itself without the need to prepend JSONString?

Currently I'm getting {"code":4,"message":"Invalid value passed for JSONString"} for every POST request I do.