- Log-in into https://account.riseup.net/
- Click on "Invites" on the left menu
- Now click on the green "Create New Invite" button.
- Copy or take write it on a paper and give it to the person you want
Please note that new accounts can't generate invite codes. After some time this feature gets enabled.
PS: We need your help to continue our work – please consider donating to riseup – https://riseup.net/donate