Hi,
Thank you for reaching out. Please see this guide for mapping TargetingideaService to the UI Keyword Planner to retrieve volume data and trends. As mentioned, you must change the RequestType to "STATS". Additionally, the data from the API might not exactly match the data from the UI as explained here.
You can use the Keyword Performance Report to retrieve performance statistics for your keywords as well. You can specify your desired date range for the values within the report definition. Please see this guide for more information about reports.
Regards,
Mitchell
Google Ads API Team