Get a custom button label in an excel file

I am trying to get the label of a custom button in a excel file, but I do not know which library to use and how to use it. Currently I use an openxlsx library but in the excel file I get all the code of the button and not just the label

Here is the useful part of my code :

# Creating a custom actionbutton
butt <- function(
  id, 
  ok, 
  data_value = 0, 
  vert = FALSE
){
  tags$button(
    id = id, 
    `data-value` = data_value, 
    class = ifelse(vert, "ok", "ko"),
    onclick = sprintf('
      $(this).toggleClass("ok ko");
      $(this).text(function(i, text){
          return text === "Ok" ? "Check" : "Ok";
        });
      $(this).data("value", $(this).data("value") + 1) ;
      Shiny.setInputValue("%s", $(this).data("value"))
      ', id), 
    ifelse(ok, "Ok", "Check")
  )
}

The reactive part in the server :

# server ====

server <- function(input, output, session) {


  #Creating the filter rule from the criteria
  create_rules <- reactive({
    paste(c(input$territoire, input$doc), "== 'Oui'",  collapse = " | ")
  })

  #Extraction of the criteria of the base
  FinalData <- eventReactive(input$submit, {
    if(is.null(c(input$territoire, input$doc)))
      return()
    else (base %>% filter_(create_rules()))
  })

  fdt <- eventReactive(input$submit, {

    r$click = data.frame(
      id = 1:nrow(FinalData()),
      ed = 0 ,
      vert = FALSE
    )

    purrr::map( # Stores the click on the buttons
      1:nrow(FinalData()),
      ~{
        observeEvent(input[[sprintf("row%s", .x)]] , {
          r$click$ed[.x] <- input[[sprintf("row%s", .x)]]
          r$click$vert[.x] %<>% `n'est pas`()

          if(r$click$vert[.x]){
            counter$countervalue <- counter$countervalue + ((1*100)/nrow(FinalData()))#Incrémente le clic dans la gauge en fonction du nombre de lignes extraites
          }
          else{
            counter$countervalue <- counter$countervalue - ((1*100)/nrow(FinalData()))
          }
        })
      }
    )

    lien_fiches = createLink(FinalData()$fiches.donnees)
    tmp_fdt <- cbind(FinalData()[1:3], lien_fiches)
    colnames(tmp_fdt) <- c("A", "B", "C", "E")
    tmp_fdt
  })

  #Réactive général
  gfilter <- reactive({
    req(fdt())
    filtered_data <- base <-  fdt() %>%
      map_df(enc2native) %>%
      mutate(
        Validation = purrr::pmap(
          r$click,
          ~ {
            butt(
              sprintf("row%s", ..1), 
              ok = ..3, 
              data_value = ..2, 
              vert = ..3
            )
          }
        )  %>% purrr::map_chr(paste)
      ) %>%
      select("A", "B", "C", "D", "E") %>%

      as.data.frame()


  #Rendering of the extraction table
  output$Synthese <-  DT::renderDT(server = FALSE, DT::datatable({

    #Affiche le tableau
    gfilter()

  },

  escape = FALSE,
  selection = "none",
  options = list(
    pageLength = 10,
    #Cache la colonne "Insee"
    columnDefs = list(list(visible=FALSE, targets=3)),

    #Extraction header color
    initComplete = JS(
      "function(settings, json) {",
      "$(this.api().table().header()).css({'background-color': '#1A242F', 'color': '#fff'});",
      "}"),
    dom="frtip",
    language = list(paginate = 
                      list('next'="suivant", 
                           'previous'="précédent"),
                    info = "Pages de _PAGE_ à _PAGES_",
                    search = "Rechercher",
                    infoFiltered = "(filtre des _MAX_ lignes)")
  )
  )
  #Sets the color of a line according to a condition
  %>% formatStyle('Insee',target="row",backgroundColor = styleEqual('Oui',"#cdd6d8"))
  )  
}

shinyApp(ui, server)

Thanks !