Not Displaying Logged In Users Avatar

Hi,

Maybe not understanding the set up instructions.

I want to place a shortcode into HTML and when that content renders it to show the current logged in users avatar not the default one. So basically need the shortcode to dynamically add the current logged in users ID to generate the correct avatar but everything i’ve tired so far either doesn’t work or crashes my website.

I need some clear instruction on how to implement this please. All users have their own avatar uploaded

Thanks in advance