POST multipart/form-data HTTP Action

I tried submitting request which requires attachment to Workday, and according to the documentation, the Content-Type needs to be “multipart/form-data”:
 

I tried via Postman and it works properly:

Now, my problem is:
How to create a HTTP Action in Agent Studio for this “multipart/form-data”?
Specifically, how to translate the <Key, Value> pair in the “form-data” section in Postman, to the “Body” section of the HTTP Action Editor in Agent Studio?
 

I searched and found a related thread, tried passing the <Key, Value> as JSON but doesn’t work:
 

May I know if HTTP Action Editor in Agent Studio is capable of such content type yet?

Thank you.