Thank you for reaching out to us on Community.
If you have the required permissions then you can enroll the TAs in your course through the Classlist tool by clicking on the Add Participants button or you can reach out to your institutional Admin who can enroll those TAs in your course.
Hi Howard. You will need to check to see if your role can enroll the TA role type on your Brigthspace. You may need to check with your administrator. If you do have the permissions set properly, you can follow the instructions on this page. You should see Add Participants button in your classlist area.