Zoho Creator Deluge InvokeUrl : How to pass form parameters to third party form? - zoho

Question

How to pass form parameters to a third-party web form with Zoho-Creator-Deluge's InvokeUrl() function?
Here is the code I have tried:
Try-1
auth_url = "https://example-form.com"
header_data = Map();
header_data.put("Content-Type","multipart/form-data");
payload = Map();
payload.put("username",app.App_Username);
payload.put("password",app.App_Password);
response = invokeurl
[
url :auth_url
type :POST
parameters:payload
headers:header_data
detailed: true
];
// debug
info response;
Try-2
auth_url = "https://example-form.com"
header_data = Map();
header_data.put("Content-Type","multipart/form-data");
payload = List();
username = {"paramName":"username","content":app.App_Username,"stringPart":"true"};
password = {"paramName":"password","content":app.App_Password,"stringPart":"true"};
payload.add(username);
payload.add(password);
response = invokeurl
[
url :auth_url
type :POST
files :payload
headers:header_data
detailed: true
];
// debug
info response;
Both Try-1 and Try-2 result in the form-page being returned in response instead of the expected logged-in page. There isn't an error message, so it seems to be ignoring the parameters in payload.
Is there a different syntax that works?
Thanks

Answer 1

Okay I found the issue was that I needed to use the Content-Type of x-www-form-urlencoded in my request headers. Here is the Try-1 updated with the working Content-Type:
header_data = Map();
//------------------------------------------------------------------
// This line is the fix!
//------------------------------------------------------------------
header_data.put("Content-Type","application/x-www-form-urlencoded");
payload = Map();
payload.put("username",app.App_Username);
payload.put("password",app.App_Password);
response = invokeurl
[
url :auth_url
type :POST
parameters:payload
headers:header_data
detailed: true
];
// debug
info response;