The goal is to change the way Matomo creates new users (ie. team members), by introducing an Invitation system. Instead of directly creating accounts for people, a Super User (or a user with Admin access) would invite a new person to join the Matomo platform, and they have to then accept the invitation (click a button in the invitation email, within a period of up to 4 weeks or so.). When accepting the invitation they can set their secure password.
The invitation solution is used in products like Github and Slack. Let us look at how they do it and get inspired?