OpenIntegrations/docs/en/examples/HTTPClient/SetResponseFile.txt

    URL = "https://httpbin.org";
    URL = URL + "/get";

    TFN = GetTempFileName();

    Result = OPI_HTTPRequests.NewRequest()
        .Initialize(URL)
        .SetResponseFile(TFN) // <---
        .ProcessRequest("GET")
        .ReturnResponseFilename();