site link: https://thehudsoncenterny.com/
Check your plugins page for Facebook-related plugins. Disable them to see which ones are creating the popups. There may be two of them—one for chat and one for social review. If you don’t want to use them, delete them.
It isnt part of the theme, you have edited a theme file and added it yourself. Either via footer.php or functions.php
deffo isnt in any BB settings just because of the way its in the footer, you might be right about the customiser footer code setting though