Your bot can only work on one website at a time. You can always switch the approved domain (and install the code) on another website to allow it to work on a different website.
By default, the bot will be applied across all pages on the domain listed in the "approved domain" field in the Configure Chatbot tab inside Instant Uploader.
If you are using WordPress (or some other site builders) you can apply logic to only have the bot appear based on conditions (i.e. repeat vs. new visitors, only on certain pages on the website, etc.)