How to add multiple header to the table?

[Chloe]

May I know how to add multiple headers to the table, similar as below, with reactable package? I see below code can draw one 2 headers, but have difficulty in 3 headers as below figure show.
(1) My first line header has multiple duplicated names
(2) I have 3 headers.

reactable(
  iris[1:5, ],
  columns = list(
    Sepal.Length = colDef(name = "Length"),
    Sepal.Width = colDef(name = "Width"),
    Petal.Length = colDef(name = "Length"),
    Petal.Width = colDef(name = "Width")
  ),
  columnGroups = list(
    colGroup(name = "Sepal", columns = c("Sepal.Length", "Sepal.Width")),
    colGroup(name = "Petal", columns = c("Petal.Length", "Petal.Width"))
  )
)

Thanks!!

[technocrat]

The flextable package does this. Code won't reprex however

suppressPackageStartupMessages({
  library(flextable)
})

ft <- flextable(airquality[ sample.int(10),])
ft <- add_header_row(ft,
                     colwidths = c(4, 2),
                     values = c("Air quality", "Time")
)
ft <- theme_vanilla(ft)
ft <- add_footer_lines(ft, "Daily air quality measurements in New York, May to September 1973.")
ft <- color(ft, part = "footer", color = "#666666")
ft <- set_caption(ft, caption = "New York Air Quality Measurements")