UTCTF2021: Web: Cutest Cookie Clicker Rip-Off (100)

This is from the UTCTF2021 CTF

Challenge Author: Aya Abdelgawad

For this challenge we are given a little hint and a URL:

It is a game with an automatic timer that count’s down. You click the cookie to earn points. The high score is 1,000,000:

Given the name and theme of this game, I look to see what cookies it uses:

Neat, it stores my high score in a cookie. Let’s bake in a better score and refresh the page:

It applied my new highest score and is counting down:

When the clock runs out, it pops up with an alert containing the flag: