Deploy manipulateWidget using R Plumber

[kmaheshkulkarni]

When I Host manipulateWidget using R Plumber it gives the following Error.

Error:

<simpleError in get(fun, mode = "function", envir = parent.frame()): object 'shiny' of mode 'function' was not found>
<simpleError in system.file(config, package = package): 'package' must be of length 1>

code:-
File Name:- html_widget.R

#' @get /plotly
#' @serializer htmlwidget
library(plotly)
data(iris)
library(plumber)
library(manipulateWidget)
varNames <- names(iris)[1:4]

plotlygraph <- function(){manipulateWidget(
  plotClusters(xvar, yvar, nclusters),
  xvar = mwSelect(varNames),
  yvar = mwSelect(varNames, value = "Sepal.Width"),
  nclusters = mwSlider(1, 10, value = 3),
  plot_ly(x = ~iris[[xvar]], y = ~iris[[yvar]], color = ~clusters,
          type = "scatter", mode = "markers") %>% 
    layout(xaxis = list(title=xvar), yaxis = list(title=yvar))
)
}

r <- plumber::plumb("html_widget.R")
r$run(host="0.0.0.0", port=8000)

                                                           regards,
                                                           Mahesh Kulkarni