Sign up with link

[val0101 (Vale)]

Is it possible to invite users to sign up with a link? Meaning that only the ones that receive the link can sign up.

[RGJ (Richard - Communiteq)]

Yes, that is possible.
See Configuring how users can create and send invites for others to join your community

[tobiaseigen]

Yes, indeed! Enable the invite only admin setting.