HiĀ Aleksandr,
Thanks for getting in touch! Unfortunately, we don’t offer any built-in options for restricting ticket sales to a specific user or group of users at this time. However, you may be able to use WordPress’s own password-protection functionality to require that invited users enter a password to access the single event page and ticket form. (This works because events are created as custom post types in WordPress, just like standard posts or pages.) You can read more about how to use this feature on WordPress’s documentation here:
https://codex.wordpress.org/Using_Password_Protection
I hope that helps! š Thanks again, and let us know if you should have any other questions!