Shiny/R: turn columns into checkbox - r

Question

I have a beginner problem. I need to turn columns into checkbox. Next, I need to assign integer values ​​to these checkbox (1,2,3) so that they are transported to the function "int<-csv()[,c(5,6,7,8,9,10)]" (where the numeric values ​​are separated by commas). Also, I need that if more than one item is selected, a comma is placed to the right of it. It is possible? Thanks in advance!
This is my code:
library(shiny)
library(shinydashboard)
library(shinyWidgets)
library(readxl)
library(tidyverse)
library(readxl)
library(stringr)
# Dashboard
ui <- dashboardPage(
dashboardHeader(
title = "Page"
),
dashboardSidebar(
sidebarMenu(
menuItem(
"Home",
tabName = "home")
)
),
dashboardBody(
tabItems(
# Home
tabItem(
tabName = "home", h2("Hello!"),
br(),
box(
width = 100,
fileInput("file", "Choose the Sheet", accept = c(
".xlsx")),
),
p("Upload Sheet", style="font-weight: bold;"),
box(
width = 200,
tableOutput("content"), style="overflow:
hidden; height: 90px; overflow-y: scroll;
overflow-x: scroll;")
)
),
)
)
# Server
server <- function(input, output, session) {
# Sheet Upload
csv <- reactive({
req(input$file)
inFile <- input$file
df<- read_xlsx(inFile$datapath)
return(df)
})
# Archive Without Extension
output$my_file <- renderText({
# Test if file is selected
if (!is.null(input$file)) {
return(str_replace(input$file$name, '\\.xlsx', ' ') )
} else {
return(NULL)
}
})
# Show Datasheet
output$content <- renderTable({
req(input$file)
inFile <- input$file
read_excel(inFile$datapath, sheet = 1, col_names = TRUE,
col_types = NULL, na = "", skip = 0)
})
output$calfa <-
renderPrint({
int<-csv()[,c(5,6,7,8,9,10)]
names(int)
})
}
# App
shinyApp(ui = ui, server = server)