I just want that the actionButton works when I click directioning the code ahead

I'm a begginer at R and Shiny. I just want that the actionButton works when I click directioning the code ahead... It's a interface where the user makes the archive.csv upload, and click on "Submmit" botton and the things continue to work ahead. This is the code:

library(bslib)
library(rmarkdown)

light <- bs_theme()

# user interface
ui <- fluidPage(
  
  theme = light,
  tags$title("WS_musteR"),
  titlePanel("MusteR"),
  includeCSS("html/style.css"),
  includeHTML("html/index.html"),
  
  sidebarLayout(
    sidebarPanel(
      fileInput("filecsv", "Insira a tabela CSV",
        multiple = FALSE,
        accept = c(
          "text/csv",
          "text/comma-separated-values,text/plain",
          ".csv"),
        width = NULL,
        buttonLabel = "Browse...",
        placeholder = "No file selected"
      ),
      
      actionButton("action", "Submeter", class = "btn-success"),
    ),
    mainPanel(
      tableOutput("contents")
      #plotOutput(outputId = "distPlot")
    ),
  ),
)

# server side
server <- function(input, output) {
  
    output$contents <- renderTable({
    observeEvent(input$filecsv, {
    file <- input$filecsv
    if (is.null(file)) {
      stop("Entrada Vazia!")
    } else {
      ext <- tools::file_ext(file$datapath)
      req(file)
      validate(need(ext == "csv", "ERROR: Please upload a .csv file!"))
      x <- read.csv(file$datapath, header = input$header)
      print("Running code...")
      source(paste0(bibpath,"main-ligs-v1_WS.R"))
    }})
  })
  
}

shinyApp(ui = ui, server = server)