How to make read_excel(file.choose()) function appear on client side in remote server shiny app

Am trying to create a shiny app that allows user upload excel file to preprocess it. I tried using the following code but the upload file appears only in the server side and the user unable to see it and upload file , what am missing ? note! if I use FileInput function I will be able to preprocess it like rename column name remove column or subset values in particular variable.

library(shiny)
library(readxl)

options(shiny.maxRequestSize = 30*1024^2)
runApp(host="0.0.0.0",port=5050,
       list(
         ui = fluidPage(
           titlePanel("Upload Excel File"),
           sidebarLayout(
             sidebarPanel(
             
               actionButton("uploada", "Upload"),
    
             ),
             
             mainPanel(
               tableOutput('contents'),
               ),
             
           ),
           
         ),

server = function(input, output){
           
           observeEvent(input$uploada, {
             
             output$contents <-  renderTable({read_excel(file.choose())})
             
             
           })
           
         }
       )
)

This cant work, you should use fileInput (which you mentioned) to load client data to a shiny app