Hi Richard, the plugin seems to do a nice job!
Detail: the text in the popup has few differences in appearance.
(1) Bold and centered when clicked at the button at this page: https://www.shiftinspiration.com/blog/start-let-the-adventure-begin (see: https://snag.gy/vwtWzX.jpg)
(2) Normal and centered when clicked at the 1st button at this page: https://www.shiftinspiration.com/test-page/ (the page you created - UPDATE: the page I created...) (see: https://snag.gy/f1NwZo.jpg)
(3) Normal and left aligned when clicked at the 2nd button at this page too: https://www.shiftinspiration.com/test-page (see: https://snag.gy/jdu23W.jpg)