insert figure in Rmarkdown beamer

Hello! I'm new to R markdown.

My problem is that when I use the simplest way of inserting a figure in a Rmd aimed to produce a beamer, it grows so gigantic that it overflows out of the beamer pdf page.


I wonder how I can insert images conveniently and properly.

Also, it couldn't be better if images are with captions, as they are in a tex output.

Can't thank you enough! x

Specifically, I wrote:

title: Pi Bond
date: "`r format(Sys.time(), '%d %B, %Y')`"
author: H
fontsize: 12pt
fonttheme: "professionalfonts"
navigation: vertical

    #theme: Antibes #clear tree
    #theme: Ilmenau #small navi line
    theme: CambridgeUS
    number_sections: true
    keep_tex: true
    keep_md: true
    toc: true
    slide_level: 3

**have a try**

>- C6H6

>- CO2