如何在shiny中将操作按钮指向插入的图(insertUI/removeUI

library(shiny)

ui <- fluidPage(
  actionButton("insertBtn", "Insert UI"),
  uiOutput("insertedUI")
)

server <- function(input, output) {
  observeEvent(input$insertBtn, {
    insertUI(selector = "#insertBtn", where = "afterEnd",
             ui = fluidRow(
               column(6, plotOutput("plot1")),
               column(6, plotOutput("plot2"))
             ))
  })

  output$insertedUI <- renderUI({
    req(input$insertBtn)
    fluidRow(
      column(6, plotOutput("plot1")),
      column(6, plotOutput("plot2"))
    )
  })

  output$plot1 <- renderPlot({
    hist(rnorm(100))
  })

  output$plot2 <- renderPlot({
    boxplot(rnorm(100))
  })
}

shinyApp(ui, server)