onclick function is not functioning properly - shiny

Question

Apparently my code looks fine to me, i have already run one such example, but these onclick() functions are not performing their job no matter what. Can anybody please help me out with that?
Its just a simple code with 6 buttons. 3 buttons for plotting scatter plot, histogram and bar plot whereas one button to hide the output div one button to show output div and one button to change the background of output div.. these onclick functions are not working :/
library(shiny)
library(shinyjs)
library(shinyWidgets)
moduleTestUI <- function(id){
ns=NS(id)
# Application title
titlePanel("My First Shiny Program")
# Sidebar with a slider input for number of bins
sidebarLayout(
sidebarPanel(
tags$style(type='text/css'
, ".btn {padding: 8px; font-size: 120%;background-color: rgb(0, 102, 204);color: white;}"
,"div.main{width: 750px;height: 550px;border-style: double;border-width: 10px;border-color:grey; }"
),
tags$div(id=ns("div1"),
hr(),
actionButton("btn",id=ns("button1"),label = "Scatter Plot"),
actionButton("btn",id=ns("button2"),label = "Histogram"),
actionButton("btn",id=ns("button3"),label = "Bar Plot"),
hr(),
br(),
actionButton("btn",id=ns("button4"),label = "Hide Output"),
actionButton("btn",id=ns("button5"),label = "Show Output"),
actionButton("btn",id=ns("button6"),label = "Change Color"))),
# Show a plot of the generated distribution
mainPanel(
br(),br(),br(),
tags$p(strong(" ***** MY OUTPUT PANEL ***** ")),
tags$div(id=ns('div2'),class="main")
)
)
}
moduleTest <- function(input, output, session){
#scatter plot
onclick('button1',
plot(mtcars$disp, mtcars$mpg,xlab="Engine displacement",
ylab="mpg", main="MPG vs engine displacement",
las=1))
#or onclick('button1',qplot(disp, mpg, data=mtcars,main="MPG vs engine displacement"))
#histogram
onclick('button2',hist(mtcars$disp,xlab="Engine displacement", breaks = 5))
#bar plot
onclick('button3',barplot(mtcars$disp, main="Graph of displacement", names.arg = mtcars$mpg))
onclick('button4',hide('div2'))
onclick('button5',show('div2'))
onclick('button6',setBackgroundColor("blue"))
#---------- other method
#scatter plot
# observeEvent(input$button1,plot(mtcars$disp, mtcars$mpg,xlab="Engine displacement",
# ylab="mpg", main="MPG vs engine displacement", las=1))
#or onclick('button1',qplot(disp, mpg, data=mtcars,main="MPG vs engine displacement"))
#histogram
#observeEvent(input$button2,hist(mtcars$disp,xlab="Engine displacement", breaks = 5))
#bar plot
#observeEvent(input$button3,barplot(mtcars$disp, main="Graph of displacement", names.arg = mtcars$mpg))
#observeEvent(input$button4,hide("div2"))
#observeEvent(input$button5,show("div2"))
#observeEvent(input$button6,setBackgroundColor("blue"))
}
ui <- fluidPage(
useShinyjs(),
moduleTestUI('test')
)
# Define server logic required to draw a histogram
server <- function(input, output) {
}
# Run the application
shinyApp(ui = ui, server = server)