How to add GA tracking code after body tag using functions.php file

Need to add GA tracking code in function.php file after body tag, i have tried using
add_Action(‘wp_body_open’ ‘function_name’). But this doesnt work? Can someone help in this

wp_body_open is the correct action to use, assuming your theme supports it.

using beaver builder child theme, this add_action is added in beaver builder child theme’s function.php file, but still it is not working

function add_google_tag() {

Google Tag Manager (noscript)  code

add_action(‘wp_body_open’, ‘add_google_tag’);

This is the code added in the function.php file

Nothing wrong with that code assuming your theme has that action.