I tried to send a post request to a PHP script with raw data. But with the given options, as in
- content types: (text, javascript, json, html, xml)
- raw data
It turned out to be not possible. Because plain text or html never sets the $_POST variable on the server side.
I could not use the given x-www-form-urlencoded option either as that requires me to set all my raw ampersand & encoded post data to be set in the key value style, I did not want that, my need (PayPal IPN Validation Callback Testing locally) was to send all this bunch of text altogether.
So in the answer you will see what I did:

Answer is explained pretty spot on on the screenshot but I will describe for the good of web here:
Content-Typeas this cannot be edited (automatically added).Content-Typefor a valueapplication/x-www-form-urlencoded