Why is ggsave not saving my plot to my computer?

Hi I'm trying to save high quality (300 dpi) images using RStudio but no luck so far. I've looked around a lot on the internet but no answer seems to work. Even when I run the code below, no file shows up on my computer. Any help is appreciated!

install.packages("gapminder")
library(gapminder)
data("gapminder")

attach(gapminder)

plot(lifeExp ~ log(gdpPercap))
ggsave("filename.png",dpi = 300)

It works fine if you use ggplot() from ggplot2 instead of plot()

Packages and data

library(ggplot2)
library(gapminder)

data("gapminder")
attach(gapminder)

Solution

ggplot(gapminder,
       aes(x =  log(gdpPercap), y = lifeExp)) +
  geom_point()

ggsave("filename.png",dpi = 300)

Here are some tweaks you came make to make it more similar to plot() appearance:

ggplot(gapminder,
       aes(x =  log(gdpPercap), y = lifeExp)) +
  geom_point(shape = 1) +
  theme_linedraw()

output from last code