To invite a new user to your account, navigate to Settings > Users.

You can invite users by entering in their email address and pressing the Invite button.

After someone has been invited, but before they've accepted their invitation, you can click the "Resend" button to send them another invitation, or click "Revoke Invitation" if you'd like to cancel it.

After someone has joined your account, you can also click the "Remove" button if you want to ensure they can't log into Daisychain again.