How to change subscribe url?

I want to change the default subscription page url to have a layer of defense against bots. i’ve changed it in settings but it seems to not work. for example i change
URL where subscribers can sign up to

but when i go to second url i get a 404 error.

You need to change a setting in the config.php file also, change the setting from /lists to /mylist


# if you change the path to the phpList system, make the change here as well
# path should be relative to the root directory of your webserver (document root)
# $pageroot = '/lists';
$pageroot = '/mylist';