Adding members to family plan LifeLock

I´m trying to add family members to the LifeLock subscription. I have 2 issues.
1—One of them received a link, but it expired. How can I get a new link? It´s impossible to find.
2- Another tried to activate it, but when they downloaded the LifeLock app on the iPhone, it asked for an existing account; the only option to create a new one was to pay for it.

Thanks

Please review: recent related:
https://community.norton.com/t/how-does-one-create-logins-for-people-on-my-account-so-they-can-see-their-notifications-if-it-s-tied-to-my-email/237469/7

https://community.norton.com/t/how-does-one-create-logins-for-people-on-my-account-so-they-can-see-their-notifications-if-it-s-tied-to-my-email/237469/8

https://community.norton.com/t/message-you-already-have-an-existing-membership-issue-case-88122096/238517/2