Hello,
UsersWP doesn’t have an integration with GetResponse so it might not work for you and GD doesn’t offer a login shortcode exactly, through there is the #loginbox widget and shortcode: https://wpgeodirectory.com/docs/core-shortcodes/#login [gd_login_box]
With GD, you can use any login or registration system you like. GD makes a login page template available to make it possible to have login and registration on the same page, resulting in more completed signups because of fewer page loads for new users, but no one is required to use that particular page.
However, GD has several interactions with site visitors where it directs them to login because login is required to access features, so, once you find a registration and login page/plugin/system you like, you can use this snippet to tell GD where the new pages are:
https://wpgeodirectory.com/docs/redirecting-the-login-page/