How to integrate leaflet map, with selectInput drop down into Shiny R.

I am attempting to create a map within Shiny R, with leaflet. I have some clear lack of comprehension on how to engineer my Shiny R leaflet map. Here are my 2 issues:

  1. How to create the map by selecting Symptoms by Country? as you can see data contains countries and symptoms in rows (see link on GitHub provided bellow). if I want to filter by a certain country and certain symptom how do I do this with leaflet in Shiny r?

  2. How do I keep it interactive on Shiny R as I have it in Rmarkdown file?

Here is the code:


server = function(input, output, session){}

    ui <- fluidPage(
        # Application title
        h1("Symptoms accross the world"),
        # Sidebar with a slider input for number of bins 
        selectInput("productCategory", "Select Country", c( "Bangladesh", "India", "Nigeria", "Pakistan", "United Kingdom")), 
        selectInput("productCategory", "Symptom", c("Chills", "Cough", "Muscle Ache"))
    server <- function(input, output) {
    # Run the application 
    shinyApp(ui = ui, server = server)

If the above code is run, then I have easily managed to create the selectInput by country and symptom. yet, do not understand how to facilitate the drop down selection for example: India with symptoms mapping such as chills. Where in the server code facilitate the filtering and how? I am very new to shiny r and honestly the language used is hardly understood by a lay person like me.

Here is the second leaflet map code I have which I do not understand how should be engineered as I want to select by country and symptom.

leaflet() %>%

map <- leaflet(gather_divided) %>% addTiles() %>% addMarkers(clusterOptions = markerClusterOptions())


Sample of a dataset is on my GitHub as I haven't found a more elegant way of deploying it to stack overflow: