if a request (typically POST) has Content-type header set to application/x-www-form-urlencoded the body is expected to be in the form of a standard querystring with url-encoded key=value pairs joined by &. Form data section then shows the key-value parameters (when viewed parsed). This way was much more common in past because it is a default for HTML forms.
other cases are shown in Request payload section (and nowadays parsed for readability as well for common formats like JSON).
如果請求的Content-Type設置為application/x-www-form-urlencoded，那么這個Post請求被認為是HTTP POST表單請求，參數出現在
其他情況如使用原生AJAX的POST請求如果不指定請求頭Request Header，默認使用的Content-Type是text/plain;charset=UTF-8，參數出現在Request payload塊。