How can I generate a ad preview without requiring the ad account id in the Facebook Ads API?

Though it is mentioned in the docs about generating a preview without requiring the ad_account_id (https://developers.facebook.com/docs/marketing-api/generatepreview/v13.0). I even follow the parameters required. However, I keep getting this error (even though the endpoint was mentioned in the docs)

"error": {
    "message": "Unsupported get request. Please read the Graph API documentation at https://developers.facebook.com/docs/graph-api",
    "type": "GraphMethodException",
    "code": 100,
    "error_subcode": 33,
    "fbtrace_id": "--"
}

Endpoint:

https://graph.facebook.com/<API_VERSION>/generatepreviews?ad_format=RIGHT_COLUMN_STANDARD&creative={ 
            "object_story_spec": { 
                "link_data": {
                    "description": "Description", 
                    "link": "<URL>", 
                    "message": "Message", 
                    "name": "Name" 
                }
            } 
        }&access_token=<Access_Token>

However, It works when using the same endpoint but with the ad_account_id on it and with the same set of test data. So I assume there is no issue with my set of test data.

https://graph.facebook.com/<API_VERSION>/act_<ad_account_id>/generatepreviews?ad_format=RIGHT_COLUMN_STANDARD&creative={ 
            "object_story_spec": { 
                "link_data": {
                    "description": "Description", 
                    "link": "<URL>", 
                    "message": "Message", 
                    "name": "Name" 
                }
            } 
        }&access_token=<Access_Token>

Maybe I'm missing something? Not really sure.

Thanks in Advance.