Mock DoubleVerify server. Based on the outline provided by the DoubleVerify IQ Connect guide. You can call the mock /dv-iqc endpoint with the params in the DoubleVerify preferred order. The hv parameter can be generated using the /hash endpoint with the same salt constant.
Here is a Postman export of sample calls to either endpoint: https://www.postman.com/collections/b6ea82038b6249368c6f