curl --request POST \
  --url https://api.headlesscommerce.io/v1/admin/products/{id}/bundle-items \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "child_product_id": "<string>",
  "quantity": 2,
  "child_variant_id": "<string>"
}
'

{
  "id": "<string>",
  "bundle_product_id": "<string>",
  "child_product_id": "<string>",
  "child_variant_id": "<string>",
  "quantity": 123,
  "child_product": {
    "id": "<string>",
    "name": "<string>",
    "slug": "<string>",
    "description": "<string>",
    "tags": [
      "<string>"
    ],
    "attributes": {},
    "images": [
      {
        "id": "<string>",
        "url": "<string>",
        "alt_text": "<string>",
        "position": 123,
        "width": 123,
        "height": 123
      }
    ],
    "options": [
      {
        "id": "<string>",
        "name": "<string>",
        "position": 123,
        "values": [
          {
            "id": "<string>",
            "value": "<string>",
            "position": 123
          }
        ]
      }
    ],
    "variants": [
      {
        "id": "<string>",
        "product_id": "<string>",
        "sku": "<string>",
        "barcode": "<string>",
        "price": {
          "amount": 123,
          "currency": "<string>"
        },
        "compare_at_price": {
          "amount": 123,
          "currency": "<string>"
        },
        "cost_price": {
          "amount": 123,
          "currency": "<string>"
        },
        "weight": 123,
        "is_active": true,
        "option_values": [
          {
            "id": "<string>",
            "value": "<string>",
            "position": 123
          }
        ],
        "images": [
          {
            "id": "<string>",
            "url": "<string>",
            "alt_text": "<string>",
            "position": 123,
            "width": 123,
            "height": 123
          }
        ],
        "inventory": {
          "id": "<string>",
          "variant_id": "<string>",
          "track_inventory": true,
          "allow_backorder": true,
          "safety_stock": 123,
          "on_hand": 123,
          "reserved": 123,
          "available": 123,
          "metadata": {}
        },
        "metadata": {},
        "created_at": "2023-11-07T05:31:56Z",
        "updated_at": "2023-11-07T05:31:56Z"
      }
    ],
    "metadata": {},
    "created_at": "2023-11-07T05:31:56Z",
    "updated_at": "2023-11-07T05:31:56Z"
  },
  "child_variant": {
    "id": "<string>",
    "product_id": "<string>",
    "sku": "<string>",
    "barcode": "<string>",
    "price": {
      "amount": 123,
      "currency": "<string>"
    },
    "compare_at_price": {
      "amount": 123,
      "currency": "<string>"
    },
    "cost_price": {
      "amount": 123,
      "currency": "<string>"
    },
    "weight": 123,
    "is_active": true,
    "option_values": [
      {
        "id": "<string>",
        "value": "<string>",
        "position": 123
      }
    ],
    "images": [
      {
        "id": "<string>",
        "url": "<string>",
        "alt_text": "<string>",
        "position": 123,
        "width": 123,
        "height": 123
      }
    ],
    "inventory": {
      "id": "<string>",
      "variant_id": "<string>",
      "track_inventory": true,
      "allow_backorder": true,
      "safety_stock": 123,
      "on_hand": 123,
      "reserved": 123,
      "available": 123,
      "metadata": {}
    },
    "metadata": {},
    "created_at": "2023-11-07T05:31:56Z",
    "updated_at": "2023-11-07T05:31:56Z"
  }
}