geom_boxplot, it won't let me plot my values, says they are not numeric

I am learning r, and I am practicing with the rivers built in dataset.

I want to make a boxplot of the river length x, but it is not working.

ex of data, full length is 141

x
735
320
325
392
524
450

my code

library(tidyverse)

rivers %>% ggplot(mapping = aes(y=x)) +
  geom_boxplot()

I get this error

Error: `data` must be a data frame, or other object coercible by `fortify()`, not a numeric vector.
Run `rlang::last_error()` to see where the error occurred.

It says it is not a numeric vector so I tried using as.numeric(x) but that did not work. It says numeric under "x" when I view it.

>Solution :

The "x" in this data for river length is a numeric vector. You should turn it into a data frame first with data.frame() Also you can change the column name from "x" to avoid any issues with the ggplot mapping.

library(tidyverse)
river <- data.frame(rivers)
river %>% ggplot(mapping = aes(y = rivers)) +
  geom_boxplot()