Valuebox is not shown in flexdashboard

My valuebox is not shown in the output, only text. Did I miss something?

title: "Untitled"
author: "June Tseng"
date: "1/12/2020"
runtime: shiny
  orientation: rows
  ource_code: embed
  vertical_layout: fill

```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = TRUE)

## valueBox

```{r pressure}
renderValueBox({valueBox(42, caption = "Test", icon="fa-thumbs-down")})

There is something off with your yaml header. Does the reprex is not correct or do you have that in your code as well ?

In flexdahsboard, headers for parts should be with ### not just two. See the doc

You also need to add a special syntax for the layout as seen in the doc too

Try without shiny first. Your example does not require shiny here.

Then you'll be able to add some shiny reactivity following the doc
and example with valueBox like the CRAN dashboard live and source

Hope it helps