Setting up wordpress multisite registration with domain name registration

Site registration is a feature that’s already built-in inside multisite core. It needs to be enabled, you can checkout this tutorial by WPMU: https://premium.wpmudev.org/blog/wordpress-multisite-masterclass-user-site-registration/

Through site registration, you give an option to your user to create a site when they register. I’m not sure there is a plugin to handle this that provides greater flexibility and customization. I didn’t find any in the plugin repo.