ACA Reporting for Union Employees - How to have system generate 2E codes?

We are pre-planning our ACA reporting for 2023. Half our workforce are union employees. Peoplesoft generates 1H codes in box 14 for them, which is correct. But in box 16 it generates 2C codes, and we have been overriding them with 2E codes. How can we set up the system to generate 2E codes for your represented employees?

Thank you!