OpenIntegrations/docs/en/examples/HTTPClient/AddAWS4Authorization.txt

    URL = FunctionParameters["HTTP_URL"];
    URL = URL + "/get";

    AccessKey = "AccessKey";
    SecretKey = "SecretKey";
    Region    = "Region";

    Result = OPI_HTTPRequests.NewRequest()
        .Initialize()
        .SetURL(URL)
        .AddAWS4Authorization(AccessKey, SecretKey, Region) // <---
        .ProcessRequest("GET")
        .ReturnResponseAsJSONObject();