Disable WordPress admin bar for all users except administrators

Paste the following in functions.php:

add_action('after_setup_theme', 'remove_admin_bar');
 
function remove_admin_bar() {
if (!current_user_can('administrator') && !is_admin()) {
  show_admin_bar(false);
}
}

Source: http://www.wpbeginner.com/wp-tutorials/how-to-disable-wordpress-admin-bar-for-all-users-except-administrators/