Ggplot is displayed without numeric limitations in its labels inside shiny app

I have the shiny app below in which I create a dynamic scatterplot. The thing is that when I create my ggplot outside of the shiny app I get it in a bigger and most readable form, but inside shiny I get the result quite smaller without numeric labels in the 2 axes. Why does this happen?

app.R

library(shiny)
library(ggplot2)

n<-structure(list(ADM3_PCODE = c("ML100101", "ML100201", "ML070301", 
"ML070105", "ML100301", "ML070107", "ML100401", "ML070104", "BF560105", 
"ML060502", "ML060302", "ML070101", "ML070202", "ML070303", "ML070204", 
"ML070205", "ML070106", "ML070305", "ML070103", "ML070102"), 
    Acled_Health = c(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
    0, 0, 0, 0, 0, 0), Acled_no_inst = c(4, 0, 0, 0, 0, 0, 0, 
    0, 3, 1, 0, 2, 1, 4, 1, 0, 1, 1, 0, 0), Acled_Total = c(4, 
    0, 1, 0, 0, 0, 0, 0, 3, 1, 0, 2, 1, 4, 1, 0, 1, 1, 0, 0), 
    I3 = c(1.09376534720521, 2.98445151003512, 1.38675338665065, 
    2.71565793377472, 3.18930523219588, 2.90551791702655, 1.53290303794127, 
    1.06882818216774, 1.0422158290422, -0.278650206004393, 1.74575777732344, 
    1.06030283919043, 1.96049964093946, 2.63957106704249, 2.58417173100033, 
    2.28469585057556, 0.531106478645378, 2.52253985112635, 2.72742421204698, 
    0.943157796157148), I4 = c(2.97790487569313, 4.39377989487155, 
    4.20062305434793, 3.5875729546847, 2.87065592255387, 1.93698960334718, 
    2.32611240844526, 3.79504053511001, 3.26867102154575, 3.54402045486982, 
    2.59943279715003, 2.24078712967162, 3.7837957824595, 0.629466739192882, 
    2.23259745421704, 3.22143437813918, 2.832868377928, 1.85546575024811, 
    2.44473249718205, 1.27700101283808), I5 = c(4.50640751725631, 
    4.59205796716096, 2.81987303382463, 5.6939014694895, 4.84552750414595, 
    3.48919571832088, 3.90947133936061, 5.62442105113242, 5.46450373445726,
3.81405499661111, 3.64136973672331, 1.48012372278708, 3.45348478980314, 
    2.79266252795185, 2.92273131958892, 3.12803195965532, 4.8713736085137, 
    4.78116333258574, 5.07934714109017, 4.90711103863146), I6 = c(4.71964925827176, 
    7.88685736651118, 4.48033628274155, 4.63463388102439, 5.41071131184507, 
    4.49985156270955, 4.81313128120664, 5.16036902503232, 4.07947495928142, 
    3.76143006251051, 5.18794193926347, 5.60747967555871, 5.50504418957362, 
    2.85716269808936, 7.16407719804625, 4.77737451764469, 5.7199718544193, 
    6.27105214031155, 3.48487832187209, 5.00715544299671), ADM0_FR = c("Mali", 
    "Mali", "Mali", "Mali", "Mali", "Mali", "Mali", "Mali", "Burkina Faso", 
    "Mali", "Mali", "Mali", "Mali", "Mali", "Mali", "Mali", "Mali", 
    "Mali", "Mali", "Mali"), ADM3_FR = c("Ménaka", "Andéramboukane", 
    "Anchawadi", "Talataye", "Inékar", "Tin Hama", "Tidermène", 
    "Ouattagouna", "Tin-Akoff", "Ber", "Banikane", "Ansongo", 
    "Bourem", "Gao", "Tarkint", "Téméra", "Tessit", "N'tillit", 
    "Bourra", "Bara")), row.names = c("2327", "4748", "7169", 
"14432", "16853", "19274", "21695", "24116", "36192", "38642", 
"41063", "43484", "45905", "48326", "53168", "55589", "58010", 
"60431", "62852", "65273"), class = "data.frame")


ui <- pageWithSidebar(
  headerPanel('Scattetrplot'),
  sidebarPanel(
    selectInput('xcol', 'X Variable', choices = c("Acled_Total", "Acled_no_inst", "Acled_Health"),selected="Acled_Total",
                                                  multiple=F),
    selectInput('ycol', 'Y Variable',  choices = c("I3", "I4", "I5", "I6" ),selected="I3",
                multiple=F),
  ),
  mainPanel(
    plotOutput('plot1')
  )
)

server <- function(input, output) {
  new<-reactive({
    myvars <- input$xcol
    newdata <- n[myvars]
    
  })
  
  
  output$plot1<-renderPlot({
    ggplot(n, aes(x=input$xcol, y=input$ycol,  fill = ADM0_FR, shape = ADM0_FR)) +
      geom_point(position=position_jitter(h=0.1, w=0.1), alpha = 0.5, size = 1.5) +
      scale_fill_manual(values=c("red","blue","orange")) +
      scale_shape_manual(values= c(23, 24, 25)) +
      geom_text(position=position_jitter(h=0.10, w=0.55),
                aes(label= ifelse(new()[,1] > quantile(new()[,1], 0.98),
                                  as.character(ADM3_FR),'')),vjust=3, size=2.75)+
      labs(x = "",y="")+
      theme_bw()
  })
  
  
}

shinyApp(ui, server)  

>Solution :

The issue is that your inputs are just character strings. Hence, doing e.g. x = input$xcol means you are mapping a constant value on the x aes, i.e. your are doing something like aes(x = "A", y = "B", ..)

To tell ggplot2 that you want to map the column of your data whose name is stored in input$xcol on an aesthetic you could e.g. make use of the .data pronoun from rlang, i.e. do x = .data[[input$xcol]]:

library(shiny)
library(ggplot2)

ui <- pageWithSidebar(
  headerPanel("Scattetrplot"),
  sidebarPanel(
    selectInput("xcol", "X Variable",
      choices = c("Acled_Total", "Acled_no_inst", "Acled_Health"), selected = "Acled_Total",
      multiple = F
    ),
    selectInput("ycol", "Y Variable",
      choices = c("I3", "I4", "I5", "I6"), selected = "I3",
      multiple = F
    ),
  ),
  mainPanel(
    plotOutput("plot1")
  )
)

server <- function(input, output) {
  new <- reactive({
    myvars <- input$xcol
    newdata <- n[myvars]
  })


  output$plot1 <- renderPlot({
    ggplot(n, aes(x = .data[[input$xcol]], y = .data[[input$ycol]], fill = ADM0_FR, shape = ADM0_FR)) +
      geom_point(position = position_jitter(h = 0.1, w = 0.1), alpha = 0.5, size = 1.5) +
      scale_fill_manual(values = c("red", "blue", "orange")) +
      scale_shape_manual(values = c(23, 24, 25)) +
      geom_text(
        position = position_jitter(h = 0.10, w = 0.55),
        aes(label = ifelse(new()[, 1] > quantile(new()[, 1], 0.98),
          as.character(ADM3_FR), ""
        )), vjust = 3, size = 2.75
      ) +
      labs(x = "", y = "") +
      theme_bw()
  })
}

shinyApp(ui, server)
#> 
#> Listening on http://127.0.0.1:4535