I haven’t seen any settings to add an API key or any place where the theme adds it to the url. Not sure if it’s a not fully developed process or if just the way it is type of thing.
The only other thing (besides waiting for support) I can suggest to try would be to add &code=API_KEY to the to the API url.
So, instead of
it would look like
Note: Be sure to replace the API_KEY with your PagePeeker api key.