DT::datatable - incorporating glyphicons - how to use independently of shiny?

[nirgrahamuk]

Hello all,
Hoping you can help me, I have an issue where I would like to be able to reproduce datatables outside of a shiny context, while retaining the lovely icon embedding functionality.
The first code reprex here, is a functioning demo, using a small shiny app, that shows a glyphicons embedding (of a thumbs-up) in the corner cell. I wish to be able to reproduce this without running a shiny app. I think its probably missing someway of attaching minified glyphicons css to the standalone version which I share below the working version. Anyone encountered this before, or know the right javascript magic to get me back on track ?

library(shiny)
library(DT)

ui <- fluidPage(
  dataTableOutput("a_DT")
)

server <- function(input, output) {
  pure_thumbupi <- icon(name = "thumbs-up", lib = "glyphicon")
  thumbupi <- as.character(pure_thumbupi)
  a_table <- tribble(
    ~Title1, ~Title2, ~Title3,
    "a cell value", "<em>emphasiseme</em>", paste0("t", thumbupi)
  )

  a_dt <- DT::datatable(a_table, escape = FALSE, options = list(
    dom = "pt", # only show the table, with pagination
    initComplete = JS(
      "function(settings, json) 
                {$(this.api().table().header()).css({
                'background-color' : '#BFD62E', 
                'color' : 'rgb(0,0,0)',
                'font-size' : '95%',
                'width' : '95%' });}"
    )
  ))
  output$a_DT <- renderDataTable(a_dt)
}

# Run the application
shinyApp(ui = ui, server = server)

The above works, but its within shiny context.
Struggling with the below:

library(shiny) # for  icon() function
library(tidyverse)
library(DT)

pure_thumbupi <- icon(name = "thumbs-up", lib = "glyphicon")
thumbupi <- as.character(pure_thumbupi)
a_table <- tribble(
  ~Title1, ~Title2, ~Title3,
  "a cell value", "<em>emphasiseme</em>", paste0("t", thumbupi)
)

a_dt <- DT::datatable(a_table, escape = FALSE, options = list(
  dom = "pt", # only show the table, with pagination
  initComplete = JS(
    "function(settings, json) 
                {$(this.api().table().header()).css({
                'background-color' : '#BFD62E', 
                'color' : 'rgb(0,0,0)',
                'font-size' : '95%',
                'width' : '95%' });}"
  )
))
a_dt

thumbless hell please advise

EDIT:
I'm editing this just to say, that I no longer require a solution to this to support my work, as I've decided to use an alternative, which are simple Ascii signifiers like blockcode 254 ■ etc. for my purpose, but it would be good to learn something from anyone that can solve the glyphicons mystery