To assign subjects to teachers, The article below will take you through.  

Kindly find the steps below helpful.

1. Click on Classes

2. Click on the Action button on the class you wish to assign a subject teacher to and select View Class (use the search box if the class is not in the display).

4. Click on Subjects.

5. Click on Assign Teacher.

5.  On the modal, click on the Select Teacher box to select the teacher's name (you can select more than one name)

6. Click on Save to complete the operation.