Example

library(plotly)

## Loading required package: RCurl
## Loading required package: bitops
## Loading required package: RJSONIO
## Loading required package: ggplot2

library(ggplot2)
ggiris <- qplot(Petal.Width, Sepal.Length, data = iris, color = Species)
ggiris

py <- plotly()
r <- py$ggplotly(ggiris)
r$response$url

## [1] "https://plot.ly/~AlexCen/17"