Your account will not be charged for using this function. You can get the results of the task within the next 30 days for free.
The cost can be calculated on the Pricing page.
Keyword Density
This endpoint will provide you with keyword density and keyword frequency data for terms appearing on the specified website or web page. You can filter and sort the data that will be retrieved with this API call.
Note: to use this endpoint, make sure the calculate_keyword_density parameter in the Task Post request is set to true