Can we make a parameter required in ESS job?

Looking to customize a seeded ESS job to make a parameter required. Under "Manage Enterprise Scheduler Job Definitions and Job Sets for Financial, Supply Chain Management, and Related Applications," I found the InvoiceGenerationJob, but in edit mode, cannot see any parameters listed, and actions is grayed out. Requirement is to LOC Number or Contract Number mandatory fields. Can anyone confirm if this is possible and how to accomplish making one of them required?