leaflet-easyPrint without Shiny

Question

I am getting closer to a solution of using leaflet-easyPrint (https://github.com/rowanwins/leaflet-easyPrint). I was able to find a solution using Shiny (Shiny leaflet easyPrint plugin), but I am not very familiar with Shiny and it seems to cause me problems in other areas. Is there a way to use leaflet-easyPrint without shiny?

I am trying to mimic the examples from https://gist.github.com/jcheng5/c084a59717f18e947a17955007dc5f92

and am able to run my map with no errors, but the button does not show up.

code:

printPlugin <- htmlDependency("leaflet-easyPrint",
                          "2.1",
src=c(href="https://raw.githubusercontent.com/rowanwins/leaflet-easyPrint/gh-pages/src/"),
                          script="index.js")

registerPlugin <- function(map, plugin) {
map$dependencies <- c(map$dependencies, list(plugin))
map}

and I have the

registerPlugin(printPlugin)

before

  onRender(
    "function(el, x) {
        L.easyPrint({
    sizeModes: ['Current', 'A4Landscape', 'A4Portrait'],
    filename: 'mymap',
    exportOnly: true,
    position: 'topleft',
    hideControlContainer: true
 }).addTo(this);}"
  )

I would love it to work like the demo http://rowanwins.github.io/leaflet-easyPrint/

Sorry if my formatting is bad. Getting used to this all still.