R Shiny + story legend in the sidebar?

Question

I would like to put a legend on one of my graphs on the sidebar of my shiny fluid page. I had two ideas for this: 1) Get the legendary coffin through ggplotly and place the sidebar, or 2) visualize the legend with the same colors and no plot on the sidebar. Unfortunately, I do not know how to do this. Any ideas? An example shines below.

library(plotly, shiny)

data <- ChickWeight
ag_data <- aggregate(data$weight,
                     list(time = data$Time, diet = data$Diet),
                     mean)  

ui <- fluidPage(

  sidebarPanel("Put Legend Here"),
  mainPanel(
    plotlyOutput("chick_weight")
  )

) # End fluid page

server <- function(input, output) {

  output$chick_weight <- renderPlotly({
    plot_ly(
      x = c(ag_data$time),
      y = c(ag_data$x),
      type = "scatter",
      mode = "lines",
      split = c(ag_data$diet),
      showlegend = FALSE
    )
  })

} # End server function

shinyApp(ui = ui, server = server)