Example of how to use shinyauthr with a shiny navbarPage UI

app.R

library(shiny)
library(shinyauthr)
library(shinyjs)

user_base <- data.frame(
  user = c("user1", "user2"),
  password = c("pass1", "pass2"), 
  permissions = c("admin", "standard"),
  name = c("User One", "User Two"),
  stringsAsFactors = FALSE
)

ui <- tagList(
  shinyjs::useShinyjs(),
  tags$head(includeScript("logout-button.js")),
  navbarPage(
    id = "tabs",
    title = "shinyauthr with Navbar Page",
    tabPanel("Home", loginUI("login"), uiOutput("homepage")),
    tabPanel("Data", tableOutput("tbl"))
  )
)

server <- function(input, output, session) {
  
  # go back to the home tab after logout
  observeEvent(credentials()$user_auth, {
    updateNavbarPage(session, "tabs", selected = "Home")
  })
  
  # call the logout module with reactive trigger to hide/show
  logout_init <- callModule(logout, 
                            id = "logout", 
                            active = reactive(credentials()$user_auth))
  
  # call login module supplying data frame, user and password cols
  # and reactive trigger
  credentials <- callModule(login, 
                            id = "login", 
                            data = user_base,
                            user_col = user,
                            pwd_col = password,
                            log_out = reactive(logout_init()))
  
  output$homepage <- renderUI({
    req(credentials()$user_auth)
    tags$h1("Something in the homepage")
  })
  
  output$tbl <- renderTable({
    req(credentials()$user_auth)
    credentials()$info
  })
  
}

shinyApp(ui, server)

logout-button.js

$(document).ready(function() {
  $(".navbar .container-fluid").append('<div class="pull-right"><button id="logout-button" class="btn navbar-btn action-button btn-danger shiny-bound-input" style="color: white; display: none;" type="button">Log out</button></div>');
});

glad to hear you found the solution you needed!

If anyone wants to know where the answer to the question is, it's here: https://community.rstudio.com/t/shinyauthr-with-shinydashboard-layout/30501/4