(In order to add students by OU the individual/user must be a Google Admin for the OU and an Admin on the Don Johnston tool.)
Login to: universalpar.com
Select: Manage students.
Select: Add students.
Click on "Import Google OU".
Click on "Proceed".
Follow Googles prompts to sign into your Organizational Unit.
Click on "Allow".
Select the OU(s) you would like to assign the "Student" permission to.**
Click on Continue.
Click on SYNC.
If you want to be notified when the OU has been added check Notify Me.
Click on OK.
It may take a few minutes for the OU to be added. You will need to log out then back in to see the changes after the sync is complete.
*Seated accounts/licenses do not have the option to add students by Google OU.
**Make sure you have any Teacher/Staff only OU unchecked.