PUT request on Magento 2 REST API through Postman

I’m trying a PUT on Magento 2 REST API through Postman like this:

https://domain/rest/V1/products/IP_X

With only a price change on the JSON content.

I’m getting the following error message:

{
    "message": ""%fieldName" is required. Enter and try again.",
    "parameters": {
        "fieldName": "product"
    }
}

The REST API spec indicates the URL to be PUT /V1/products/:sku and the JSON should include only the parameter to change.

Any idea?