Nicht-Admins oder Usergruppen in WordPress nicht in den Admin-Bereich lassen & Admin-Bar ausblenden.php

#region Redirect non-authors back to profile page when accessing /wp-admin
function nxt_redirect_non_admin_user() {
	if(!defined('DOING_AJAX') && !current_user_can('edit_posts')) {
		wp_redirect(site_url() . '/my-account/');
		exit;
	}
}
add_action( 'admin_init', 'nxt_redirect_non_admin_user' );
#endregion Redirect non-authors back to home page when accessing /wp-admin

#region Disable the WP admin bar for non-authors
add_filter('show_admin_bar', function($show) {
	if(!current_user_can('edit_posts')) {
		return false;
	}
	return $show;
});
#endregion Disable the WP admin bar for non-authors 

To prevent everything below...

• admin -> use !current_user_can('edit_plugins');
• editor -> use !current_user_can('delete_others_posts');
• author -> use !current_user_can('publish_posts');
• contributor -> use !current_user_can('delete_posts');