G4sp4rCS/htb-academy-skills-assestment-using-web-proxies ? reverse-engineered prompt

Build me a small Python script that automates the last step of this Hack The Box Academy web proxies challenge.

I want it to take the decoded cookie value, notice that it is 31 characters long, and brute force the missing last character by trying all alphanumeric options. For each guess, it should apply the same encoding steps needed for the proxy challenge, send the request, and stop when it finds the right one.

Make it easy to edit the target URL, cookie name, and any headers or proxy settings. If it helps, use the alphanum case wordlist idea from SecLists, but keep it simple and self contained. Also print useful progress so I can see what it is testing and when it finds the valid response.

If there’s anything unclear about the encoding or request flow, inspect the README and make a reasonable assumption, or look up current docs online if you need to.