The Json format that should be used for the posted message. The ‘flat’ format presents a single level json object and ‘nested’ is a structured json format.
query-string
string
optional
-
sets the custom query string of the webservice service. The query string MUST NOT be URL encoded, and MUST NOT contain the query string leading character ’?’, e.g. ‘field1=value1&redirect=https://localhost/callback’ or ‘a,b,c,d’