Plot forecast() with dates in my x-axis in R-Shiny

I am trying to calculate and plot a forecast based on the moving average. Unfortunately, I can not manage to have the forecast displayed with an x axis representing the dates. I get a plot without dates based on my R Shiny code:

  output$forecast<- renderPlot({ 

    ts <- getSymbols(input$symb
                     , from = input$dates[1]
                     , to = input$dates[2]
                     , warnings = FALSE
                     , auto.assign = FALSE)        
    
    df <- data.frame(ts) #convert into data frame
    
    names(df) <-c("Open", "High", "Low", "Close", "Volume", "Adjusted")
    
    df$Date <- as.Date(rownames(df))
    
    df$MA10 <- TTR::SMA (df$Close, n = 100)
    
    ts <-  df$MA10 %>% ts
    
    fma <-forecast (ts, h=100)

    main_label <- paste("100 days forecast based on moving average",
                        "\n",
                        names(which(codes == input$symb))," - ", input$symb,
                        "\n",
                        input$dates[1]," - ",input$dates[2]
                       )
    
    plot(fma, xlab ="Days", ylab = "Closing prices", main = main_label)
    
    
  })## End renderPlot

Is it possible to somehow include the dates into my graph? It currently looks like this: Forecast Plot RShiny