Unable to Define Lump Sum Amount for Mileage Category Rates

Our business requires the ability to define a lump sum amount for certain mileage categories in addition to the per-mile rate. This lump sum amount needs to be specified to ensure accurate and fair reimbursement to employees for their mileage expenses.

We have defined mileage category rates in our Oracle Fusion Expenses module as per our business requirements. However, we are unable to locate the option to define a lump sum amount for the mileage category.