create expense for per diem through rest API with details for the deductions

Summary:

We are building an APEX tool for travel request. To capture the full expected cost, we are including the per diem calculation for this travel request. This is possible by building the necessary screen and running the API to calculate the per diem amounts.

Once the travel is approved, we will transfer the expected expense report to the ERP to be finalized by the employee once the trip is over. We succeeded in creating the expense line for the per diem that includes deductions. But I have not found how I can submit the details of the deductions while creating an expense line with the API.