Multiple Shiny apps called as scripts inside main application

Question

I am creating a Shiny app using structure as below:

library(shiny)
library(ggplot2)

dataset <- diamonds

ui <- fluidPage(

  title = "Diamonds Explorer",
  
  plotOutput('plot'),
  
  hr(),

  fluidRow(

selectInput("script", "Script:",
                c("Script1" = "cyl",
                  "Script2" = "am",
                  "Script3" = "gear"))
    )
  )
)

Inside fluidRow I want to execute different small shiny apps cyl, am, gear producing different plots. Apps should be like in example below:

App cyl:

ui.R

# k-means only works with numerical variables,
# so don't give the user the option to select
# a categorical variable
vars <- setdiff(names(iris), "Species")

pageWithSidebar(
  headerPanel('Iris k-means clustering'),
  sidebarPanel(
    selectInput('xcol', 'X Variable', vars),
    selectInput('ycol', 'Y Variable', vars, selected = vars[[2]]),
    numericInput('clusters', 'Cluster count', 3, min = 1, max = 9)
  ),
  mainPanel(
    plotOutput('plot1')
  )
)

server.R

function(input, output, session) {

  # Combine the selected variables into a new data frame
  selectedData <- reactive({
    iris[, c(input$xcol, input$ycol)]
  })

  clusters <- reactive({
    kmeans(selectedData(), input$clusters)
  })

  output$plot1 <- renderPlot({
    palette(c("#E41A1C", "#377EB8", "#4DAF4A", "#984EA3",
      "#FF7F00", "#FFFF33", "#A65628", "#F781BF", "#999999"))

    par(mar = c(5.1, 4.1, 0, 1))
    plot(selectedData(),
         col = clusters()$cluster,
         pch = 20, cex = 3)
    points(clusters()$centers, pch = 4, cex = 4, lwd = 4)
  })

}

Each of this apps is saved in different scripts. How can I call this scripts based on some user selection as inside fluidRow?

Regards