If an additional field is active it will be displayed in the admission form, and if we do not want a custom admission detail field to be displayed in the student admission form, we can inactivate it or delete it. However, we cannot delete a custom admission detail field that has already been used to record student details.
At the top of your dashboard, click the module access icon > Administration > Settings > Add Admission Additional Details to open the Add additional details page.
Click Edit beside the custom admission detail field to edit, select the Inactive status, and then click the Update button. Custom admission detail fields that are inactivated are moved under the Inactive Fields list.
Click Delete beside the custom admission detail field if you want to delete.
For more information, watch this-