urgent!!!! ask about accounts for observer (parent of children)

Community Novice

Currently our school has 1302 students and we have a need to create a list of parents for students to monitor their children's academic progress. I created a list observer_user.csv and imported it into the canvas instructure.
Parents of students log in normally and see their child's progress.
The question is: is there a charge for creating many of these observer accounts? Or it's completely free and we want to create as much as we want.
need experts of canvas instructer or experienced friends to help me with my question.

Thank you,