Do you know any multisite plugin which allows users to create a user account and a site after a form submission. After the form submission, the form will automatically add a site in the network admin and create a new user. Is this possible? Some say that it needs hardcoding for it to work. But I have no idea how to. Hope you guys can help.
create a form, same as contact or custom content from frontend and send the content of field with the WP core function
an example without form, only a function to insert users and see the fields for the data array.
I think is an good idea, that you check the user, before you add the entry on email or name. But you can also update via function: