1) Once you are logged in, click Users / Logins
2) Click Invite User
3) Add email, select role, and add them to groups (optional)
4) Once everything is filled out click Save
The new user will receive an email from NRDS confirming that they are registered with a link to set a password and fill in their name. The new user will need to click on the link and it will take them to the password creation screen where they can set their password then log into NRDS.