Forum Thread: Payload Processing on Burp(?)

Hey everybody I'm new here and on forums generally, I don't know if this is the place to ask but today I was playing a little with burp and tried to brute force with the "Intruder" section some of my account on different websites but on one of them I noticed that before being sent the password was somehow "encrypted"(?), so even entering the right password it wouldn't recognize it as right. Is there a way to understand how exactly it has been converted in order to be able to copy it on the "payload processing" section?