Interact with the shadow DOM in Selenium
See here for the original answer.
What I noticed when using the Selenium head to manually debug is that the cookie element does not show up on my machine. If you have anything on your browser/machine that could be preventing the cookie popup, that may be a factor.
An additional problem is that the tiktok-cookie-banner element uses the shadow DOM, which introduces a whole separate element of complexity. To solve this problem, I recommend the shadow-automation-selenium package, which the documentation explains how to use to interact with the element you are interested in. More information about the shadow DOM can be found in this thread.