Getting viewers back

What do you mean when you say viewer? A user account?

It sounds like you may be describing a WordPress.com site, which we really can’t help with here.

To clear up any confusion, WordPress.com and www.ads-software.com are two different entities: https://www.ads-software.com/support/article/wordpress-vs-wordpress-com/

WordPress.com has complete documentation and support contacts at https://wordpress.com/support/

With that said, the only way to add a viewer back to a private site there is to invite them again: https://wordpress.com/support/user-roles/#adding-users-to-your-site