404 NOT FOUND ERROR

[prosper-20]

Hey Mitch. First off, very lovely tutorial, although I'm currently stuck in the "Finishing the REST API (User Serialier) section. I noticed whenever I update a user's properties(i.e email and username), I get a 404 response whereas I'm able to view the user's properties(email, username, pk). Please, I need your help with this. What am I doing wrong?