R Error: 'geom_lollipop' Function Not Found - Solution

It seems that the function 'geom_lollipop' is not a standard function in R. It's likely part of the 'ggalt' package, which you'll need to install and load before using it.

Here's how to install and load the 'ggalt' package:

install.packages('ggalt')
library(ggalt)

After running these commands, you should be able to use the 'geom_lollipop' function without any issues.