Open Group → Folk and use the suggestion option to choose someone you already know through AmongFolk. This does not search your phone contacts or let you discover strangers.

If the owner does not already know that person through a group, the person is asked first whether their name can be passed on. The owner sees the suggestion only after they agree. A refusal is not shown to the suggester or owner.

The owner can then send an invitation. The invited person still chooses whether to accept it from You. Suggesting a person, or paying for a group with Together, never adds them automatically.