Custom functions not found when using future/furrr packages

[leeroyaus]

I'm trying to use custom functions stored in the utils_helper.R file in a golem Shiny App with packages like future/furrr/rmarkdown but the custom functions can't be found.

When using custom function with future/furrr packages, the error message is:
Error: there is no package called 'packageName'
where packageName is the name of the golem Shiny App.

An example of this is below:

app_ui

#' The application User-Interface
#'
#' @param request Internal parameter for `{shiny}`.
#'     DO NOT REMOVE.
#' @import shiny
#' @noRd
app_ui <- function(request) {
  tagList(
    # Leave this function for adding external resources
    golem_add_external_resources(),
    # Your application UI logic
    fluidPage(
      plotOutput("plot")
    )
  )
}

#' Add external Resources to the Application
#'
#' This function is internally used to add external
#' resources inside the Shiny application.
#'
#' @import shiny
#' @importFrom golem add_resource_path activate_js favicon bundle_resources
#' @noRd
golem_add_external_resources <- function() {
  add_resource_path(
    "www",
    app_sys("app/www")
  )

  tags$head(
    favicon(),
    bundle_resources(
      path = app_sys("app/www"),
      app_title = "renderRmd.shinyapps.io"
    )
    # Add here other external resources
    # for example, you can add shinyalert::useShinyalert()
  )
}

app_server.R

#' The application server-side
#'
#' @param input,output,session Internal parameters for {shiny}.
#'     DO NOT REMOVE.
#' @import shiny progressr future furrr
#' @noRd
app_server <- function(input, output, session) {
  output$plot <- renderPlot({
    X <- 1:24
    plan(multisession(workers = 6))

    future({
      msgFunc()
    })

    withProgressShiny(message = "Calculation in progress",
                      detail = "This may take a while ...", value = 0, {
                        p <- progressor(along = X)
                        y <- future_map(X, function(x) {
                          Sys.sleep(1)
                          msgFunc(x) #If comment out this line, the app works
                          p()
                        })
                      })
    plot(cars)
  })
}

utils_helper.R

#' helpers
#'
#' @description A utils function
#'
#' @return The return value, if any, from executing the utility.
#'
#' @noRd

msgFunc <- function(x){
  print(
    paste(
      "Calculating",
      x
    )
  )
}

@ColinFay provided a solution (used above) but this isn't working for me

I also tried using a similar solution when rendering an Rmd file that used custom functions, but this also didn't work

Thanks for the assistance