Question about finding coords for splash_click

[Jjohn987]

I'm trying to use splashr's splash_click() function. As I work through the example at the bottom of the splashr tutorial, it doesn't seem to work for me.

The png that returns to me is covered up by the pop-up that initially appears when visiting the site. The documentation specifies that coords for the click function need to be "relative to viewport". I'm not sure what that means, but I'm guessing mine aren't.

How can I be sure I am using the right coords?

splash_local %>% splash_plugins(TRUE) %>% splash_go("https://gis.cdc.gov/GRASP/Fluview/FluHospRates.html") %>% splash_wait(4) %>% splash_click(460, 550) %>% splash_wait(2) %>% splash_click(230, 85) %>% splash_wait(2) %>% splash_png()