Update product item price.

curl --request POST \
     --url https://app.amberflo.io/payments/pricing/amberflo/account-pricing/product-item-price \
     --header 'accept: application/json' \
     --header 'content-type: application/json' \
     --data '{
     "price": {
     "type": "DimensionCounterWindowFunctionNode",
     "nextNode": {}
     },
     "subscriptionPrice": {
     "type": "DimensionCounterWindowFunctionNode",
     "nextNode": {}
     },
     "subscriptionPriceGenerator": {
     "id": "",
     "leafNodeType": "",
     "newEventDimensions": [],
     "newTimeWindow": "",
     "priceTiers": [
     {}
     ],
     "productItemId": "",
     "type": "ultra_frequency"
     },
     "subscriptionSettings": {
     "cancellationRule": "",
     "chargeExecution": "",
     "purchaseRule": "",
     "subscriptionRate": ""
     },
     "priceGenerator": {
     "dimensionKeys": [],
     "productItemId": "",
     "priceTiers": [
     {
     "leafNodeType": ""
     }
     ],
     "type": "cost_plus_dimension"
     }
     }'