Base 64 Encoding in Designer 2019.2?

[Archaeopteryx]

Hi,

I would like to use Alteryx Designer to make an API call to a server to send me a fresh Authorization Token when I provide the Client-ID and Client-Secret. The Authorization Token expires on this server every 48 hours, which is why I want to set up this workflow to fetch it for me.

I have to Base 64 Encode those two provided keys to receive the payload I'm requesting. It works in Postman by just providing it in the Header section with "content-type" = "application/x-www-form-urlencoded". Can someone share with me how I can send this request base 64 encoded in Alteryx Designer. I'm using version 2019.2. 

thank you,

Chris

[Archaeopteryx]

With a lot of experimentation and just messing with the Download tool's Payload and Header tabs, I got this to work with just two tools. 

I had to create a Header called, "Content-Type" with "application/x-www-form-urlencoded" as its value. That's all it took to encode the request payload parameters.