How to add discounts on both entity_level and items_level in Sales Order? – Woocommerce

I’m trying to integrate ZOHO books invoice system with Woocommerce. I’m creating a sales order using API which is later converted into an Invoice and trying to add discounts for both levels. One in items_level that is attached with line items and another in entity_level should be applied on the subtotal of line items before the tax calculation.

The issue I’m facing is the API applying the discount only at entity_level(ignoring items_level), whereas I’m adding discounts for both in the API request body. (See the attachment)

Request body:

{
        "customer_id": "123456789",
        "date": "2022-03-05",
        "shipment_date": "2022-03-05",
        "is_inclusive_tax": false,
        "place_of_supply": "DL",
        "salesperson_name": "ABC",
        "gst_treatment": "consumer",
        "line_items": [
          {
             "rate": '999',
             "name": "Product_Name",
             "description": "Product_Descp",
             "quantity": 1,
             "product_type": "goods",
             "discount": "10%",
             "tax_id": "123456000",
             "hsn_or_sac": "200200"
          }
        ],
        "billing_address_id": "12347890",
        "shipping_address_id": "12347891",
        "tax_id": "123456000",
        "discount": "202.89"
        "shipping_charge": "40",
        "delivery_method": "delivery_method_name",
    }

I want both to work together because I need to show coupons discounts at entity_level (if coupon applied during checkout) and sales discount at items_level.
Is there any setting or any other way to add discounts on both levels simultaneously?

Any help will be much appreciated!

Thanks,