Configure Plotly download plot button with Shiny

Question

I'm trying to configure the download plot button to output an image in 'svg' format. I'm working on a shiny app with R. I render the plot using renderPlotly() function after the following occurs:

• user selects parameter my_TSG from selectizeInput()
• parameter my_TSG is parsed and passed to server accordingly: TSG_at_server
• TSG_at_server calls a file path
• requested data is loaded to server (from pool of all the data available; to reduce log times) ("*_raw")
• requested data is transformed
• plot is created and called to output$volcano_celllines using renderPlotly()

Currently Plotly v.2.11.1 downloads plots .png and would like to make it format = 'svg'.

I'm aware of config(fig, toImageButtonOptions = list(...) ) but I do not know how to implement that re-configuration of Plotly within my app.

Please note, App is more complicated than this so hope I simplified it to a reprex that is understandable.

Alternatively, I'm looking for a solution to downloading the plot with higher resolution in png.

######### UI side ##################

ui <- fluidPage( 
    sidebarLayout(
        sidebarPanel(
            selectizeInput( 
                inputId = "my_TSG"
                ),
        
            # button confirm TSG
            actionButton(
                inputId = "confirmTSG",
                label = "Confirm TSG", 
                class = "btn btn-default btn-xs"
                ),

            actionButton(
                inputId = "goButton",
                label = "Run analysis"
                )

        ),  # end of sidebarPanel()


        # Show a plot of the generated analysis
        mainPanel(
            tabsetPanel(
                type = "tabs",
                tabPanel(
                    title = "Plot",
                    plotlyOutput(outputId = "volcano_celllines", height = 625))
                    )
            )   # end of tabsetPanel()
        )   # end of mainPanel()
    )   # end of sidebarLayout()
)   # end of fluid page()



######### server side ##################

server <- function(input, output, session) {

    TSG_at_server <- eventReactive( input$confirmTSG, {rownames(TSG.symbols[match(input$my_TSG, TSG.symbols$'Tumour Supressor Gene')]} )


    ######### load required data for plotting #######################
    SL_data_celllines_raw <- {

        reactive({req(input$my_TSG)})   

        file_SL <- reactive({   
        file.path(data.dir, paste0(TSG_at_server(), "/", TSG_at_server(), "_SL.txt.gz"))
        })
            
        reactive({ read.table(gzfile(file_SL()), header = TRUE, sep = "\t", stringsAsFactors = FALSE) })

        }


    SL_data_celllines <- {
        reactive({ cbind(SL_data_celllines_raw(), "gene_symbol" = SL_data_celllines_raw()$label) })
        }


    ########## create plot ######################
    plt.SL.tab1 <- eventReactive(input$goButton, {

        ggplot(
            data = SL_data_celllines(),
            aes(x = Effect, y = Pval)
            ) +
        geom_point(
            alpha = 0.3
            )

        })


    output$volcano_celllines <- renderPlotly({ plt.SL.tab1() })

}   # end of server function

########## Run the application ##################
shinyApp(
ui = ui,
server = server
)