R/ShinyApp not showing plot_ly in browser but show only graph in viewer pane

Just an example that how it solved my problem.

ui <- dashboardPage(
  dashboardHeader(title = "Basic dashboard"),
  dashboardSidebar(),
  dashboardBody(
   fluidRow(
    box(plotlyOutput("plot1", height = "400px", width = "600px"))   
   )
  )
)
server <- function(input, output) {
set.seed(100)
d <- diamonds[sample(nrow(diamonds), 1000), ]
output$plot1 <- renderPlotly({
  plot_ly(d, x = ~carat, y = ~price, color = ~carat,
        size = ~carat, text = ~paste("Clarity: ", clarity))    
 })
}
shinyApp(ui = ui, server = server)