I don’t have a cengage account, so I can’t actually do do anything with the Python and test it, and I’m obviously unaware of the http responses you get from the site or how any of it works.

Two things jumped out at me while glancing through the script though. First, you close the login tab, then when you try to parse the html content from the ebook tab you reference tab [1]. I usually use the requests library bc I’m posting payloads and stuff so I rarely use selenium, and I’ve never fucked with tabs, but with the first tab closed won’t the ebook tab be first in the index, so [0]? Second, look up how to set a proxy for selenium, download the community edition of burp suite, then proxy all your traffic in the script through burp. You’ll then be able to see all your http requests and all the http responses from the server, which will probably help you debug much more effectively.

Edit - if you even care anymore haha.