I would like to dynamically update the choices of a checkboxGroupInput in R Shiny using a vector.
However, a vector used in updateSelectInput does only create text without boxes whereas directly in checkboxGroupInput it works.

What is the problem, and how to solve it?

Sadly, I could not find a solution while searching the internet.

MWE:

library(shiny)

ui <- fluidPage(
  actionButton("gobutton", "Update Buttons"),
  checkboxGroupInput("dynButtons", "Buttons", choices=NULL),
  checkboxGroupInput("demo", "Expected result:", choices =c("5-6","5-67","1-1"))
)

server <- function(input, output) {

  buttonPressed <- eventReactive(input$gobutton, {
    TRUE
  })


  observeEvent(buttonPressed(), {
    updateSelectInput(inputId = "dynButtons", choices = c("5-6","5-67","1-1"))
  })

}

shinyApp(ui = ui, server = server)