Add a action to enqueue stylesGist for my "WorpdPress: Css Styles and Javascripts in theme development (In depth)" article: https://since1979.dev/wordpress-css-styles-and-javascripts-in-theme-development-in-depth/

functions-styles-scripts-async.php

<?php
function my_theme_optimize_script_tags( $tag , $handle , $src )
{
  /* add async defer attributes */
  $defer = ( $handle == 'my-theme-scripts' ) ? 'async defer' : '';
  
  return "<script id='{$handle}' {$defer} src='{$src}'></script>" . "\n";
}

add_filter('script_loader_tag', 'my_theme_optimize_script_tags', 10, 3);
?>