How to format the tick labels of the noUiSlider with SI symbols?

Here is how my noUiSlider looks like:

enter image description here

I would like to format the tick labels as: 1000 -> 1K, 900000 -> 900K, 5000000 -> 5M, etc; i.e. abbreviating the number with the appropriate SI symbol.

library(shiny)
library(shinyWidgets)

ui <- fluidPage(
  
  tags$br(),
  
  noUiSliderInput(
    inputId = "noui", 
    label = "Slider vertical:",
    value =  50,
    orientation = "vertical",
    range = list("min" = list(0),
                 "25%" = list(1000, 500),
                 "50%" = list(10000, 50000),
                 "75%" = list(4000000, 500000),
                 "max" = list(10000000)),
    pips = list(
      mode = "values",
      values = list(0, 500, 1000, 900000, 5000000, 10000000),
      density = 4
    ),
    format = wNumbFormat(decimals = 0),
    width = "300px", height = "300px"
  ),
  verbatimTextOutput(outputId = "res")
  
)

server <- function(input, output, session) {
  
  output$res <- renderPrint(input$noui)
  
}

shinyApp(ui, server)