The users in the small circle are quite mixed. Compared with the same type of application, I prefer to be strict, and he doesn't need an invitation code. You can register directly for use. Moreover, the audit is strict, and the user's group image has the same purpose. It is easier to communicate and make friends.

After receiving the information containing the invitation code and the registered address, the invitee clicks on the registered address, copies the invitation code, and pastes it in the invitation code column when registering to complete the invitation registration.