Updating sales quote item price (calculated amount) via Odata

[chackoanil]

I am trying to update price details of a sales quote item via c4c odata api.

Via the api, I am able to create the rate and type of each external price component for a sales quote item.

When I am doing a patch request to update calculated price of the item with the following format.

URL : /sap/c4c/odata/v1/c4codataapi/SalesQuoteExternalPriceItemCollection('ObjectID')

Body:

{ "CalculatedAmount":"1501.00"}

The api provides the response

'Only rate and type allowed for quote external price components'

When I check the Metadata of odata api for SalesQuoteExternalPriceIItem, it shows Calculated amount is updatable.

What is the reason for this response message? Is it a system limitation, or am I missing any configuration?