If the status is Government of Canada, Native Education Authority, Other Student – Outside Ontario, or Study Permit/Temporary Resident, then the Payment of ‘OP’ Fees is available to select from the list of boards, if necessary. ‘OP’ refers to Other Pupils on the enrolment registers. 

When selecting payment of "other pupils" fees and you don't see the options you need follow the instructions below.

Student record>enrollment>enrollment register info> edit 

For this example, I added TEST under the boards to show it will appear in this drop down

How to add new "other fees" Board level>setup>schooling info>Boards

Click on the plus and add in your new "other fees"

Enter in all mandatory fields>Save

Your option that was entered will be available for all schools under student enrollment register info.