HTTPRequest POST with BLOB?

Trying to send a blob with HTTPRequest VIMP, but doesn’t seem to work.
According to : Documentation
if type is “string”, data can be either string or blob. The server doesn’t receive the value: field but does receive target: and channel: fields.

local data = blob(64);
for (local i = 0; i < data.len(); i++)
data[i] = i + 33;

local output = OutputPort(“DataSend”, “string”);
imp.configure(“Data Sender”, [], [output]);