.HTML file rendered with rmarkdown by reveal.js presentation is not showing embed .GIF with <iframe

Question

I'm tryng to embed a .gif file inside of a reveal.js presentation using Rmarkdown, but this is not shown in the rendered file. I coded with iframe:

<iframe src="https://giphy.com/embed/7K3p2z8Hh9QOI" width="480" height="270" frameBorder="0" class="giphy-embed" allowFullScreen></iframe>

I setted the .Rmd file this way:

output:
  revealjs::revealjs_presentation:
    transition: fade
    mathjax: null
    incremental: true
    theme: simple
    center: false
    reveal_options:
       slideNumber: true
   self_contained: false
   fig_width: 6
   fig_height: 3.5
   reveal_plugins: ["zoom"]
   controls: false
   mouseWheel: false

What do you thing it's happen?

Answer 1

The gif is shown with any browser (external)!! (not locally when i render it in RStudio)