проверьте этот код:
library(highcharter)
data(citytemp)
hc <- highchart() %>%
hc_xAxis(categories = citytemp$month) %>%
hc_add_series(name = "Tokyo", data = citytemp$tokyo) %>%
hc_add_series(name = "London", data = citytemp$london) %>%
hc_legend(align = "right", verticalAlign = "bottom",
layout = "horizental", y = -5)
hc