get response header variable in Shiny

My apache passes LDAP login to variable X-Remote-User in header:

but I don't know how to get it in Shiny app. Any ideas? Maybe solution could be some java script?

Ok I resolved it. Firstly include in ui.R js function:

www/js/getLogin.js:

function requestLogin() {
var client = new XMLHttpRequest();
client.open("GET", "yourshinyhostname", true);
client.send();
client.onreadystatechange = function() {
    
var resposne = client.getResponseHeader("X-Remote-User");
Shiny.onInputChange("getLogin", resposne);
}; }

Then you can get X-Remote-User value for example by clicking button:

ui.R:

includeScript("www/js/getLogin.js"),
uiOutput("login_btn"),
verbatimTextOutput("text")

server.R :

output$login_btn <- renderUI({
  
  HREF <- sprintf('
                  <button id="get_login_btn" value="test" onclick="requestLogin();" >
                  <font color="black">
                  <i class="fa fa-user"></i> Get login
                  </font> 
                  </button>
                  ')
HTML(HREF)
}) 

jsOutput <- reactive({
  input$getLogin
})

output$text <- renderPrint({ 
  jsOutput()
})