Retrieve the Report
Next, you’ll make a GET request to the /GetStatement endpoint, again passing your access token. However, the reference code obtained from the prior endpoint must now be passed for the q query parameter:
https://ndcdyn.interactivebrokers.com/AccountManagement/FlexWebService/GetStatement?t={AccessToken}&q={ReferenceCode}&v=3
Depending on the size of the request, you may need to wait longer between the /SendRequest endpoint and /GetStatement endpoint calls for the full report to finish generating.
Note that a given Flex Query template can be used to generate multiple reports over time, each populated with data at the time of generation, so this ReferenceCode identifier is used to retrieve a specific instance, presumably the one generated immediately prior.
The returned values will be constructed using "Content-Type": "text/plain;charset=UTF-8".

