I clicked "Accept" because I didn't want to deal with it later, especially given the new terms, and Claude training on new chats and resuming existing chats from September 28th,

but the "Accept" and "Not Now" are for the new terms of use.

So by toggling off and clicking "Accept", it will accept the toggled version. You can check the setting after accepting it at: https://claude.ai/settings/data-privacy-controls It's the "Help Improve Claude" button.