Category Search in Yelp is not Filtering properly in nodejs. I have given category as "Restaurants" but my o/p is : parks and Playgrounds

I have been trying to implement the business search in yelp fusion. But I couldn't get the results, I have given the category in order to get filtered code:

            function yelpSearchReuslt(latitude,longitude,radius,listOfResult){
                const searchRequest = {
                    categories:"Restaurants",
                    latitude:latitude,
                    longitude:longitude,
                    radius:radius
                };
                const client = yelp.client(API_KEY);
                client.search(searchRequest).then(response => {
                    const firstResult = response.jsonBody.businesses;
                 })

In the o/p I am getting categories like Playground and parks o/p:

{
            "id": "U2lT4qo4R80vsYKUFaBoCA",
            "alias": "lost-hills-wonderful-park-lost-hills",
            "name": "Lost Hills Wonderful Park",
            "image_url": "https://s3-media1.fl.yelpcdn.com/bphoto/t5y8zHqDfx5mN2v7wtvUxw/o.jpg",
            "is_closed": false,
            "url": "https://www.yelp.com/biz/lost-hills-wonderful-park-lost-hills?
adjust_creative=KOlGv8v3EO9ZpCUlYru9eg&utm_campaign=yelp_api_v3&
utm_medium=api_v3_business_search&utm_source=KOlGv8v3EO9ZpCUlYru9eg",
            "review_count": 10,
            "categories": [
                {
                    "alias": "playgrounds",
                    "title": "Playgrounds"
                },
                {
                    "alias": "parks",
                    "title": "Parks"
                }
            ],
            "rating": 4.5,
            "coordinates": {
                "latitude": 35.6164124330499,
                "longitude": -119.689275188145
            },
            "transactions": [],
            "location": {
                "address1": "14688 Lost Hills Rd",
                "address2": "",
                "address3": "",
                "city": "Lost Hills",
                "zip_code": "93249",
                "country": "US",
                "state": "CA",
                "display_address": [
                    "14688 Lost Hills Rd",
                    "Lost Hills, CA 93249"
                ]
            },
            "phone": "+16614482149",
            "display_phone": "(661) 448-2149",
            "distance": 13784.418058437912
        }

from Category Search in Yelp is not Filtering properly in nodejs. I have given category as "Restaurants" but my o/p is : parks and Playgrounds