How can I change Student Fee Category if fees are not paid?

1. Navigate to Settings > Finance > Fee > Student Fee Category.
2. Go to Allocate Students.
3. Choose the Class and Section.
4. Search for the student, then click on the fee type code circle next to that student.
5. Choose the new fee category as per your requirement.
6. Click continue to map it.

The new category will be allocated and assigned to that student.