Why can't they store normal json on their api?

this is my fetch:
getDailyMenus(){
        return fetch("https://developers.zomato.com/api/v2.1/dailymenu?res_id=17937272", {
          headers: {
            Accept: "application/json",
            "User-Key": "api key from zomato"
          }
        })
            .then((data) => data.json())
                .then((res) => {this.setState({dataSource: (res)});console.log(res)})
                    .catch((err) => {Alert.alert("Error!"); console.log(err);
                ;});
    }
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and this is the response (log from console):
Object {
  "daily_menus": Array [
    Object {
      "daily_menu": Object {
        "daily_menu_id": "20201786",
        "dishes": Array [
          Object {
            "dish": Object {
              "dish_id": "688202608",
              "name": "Polievka: Kulajda so strúhaným vajíčkom A:",
              "price": "1,90 €",
            },
          },
          Object {
            "dish": Object {
              "dish_id": "688202609",
              "name": "I. Bravčové Polpette so syrom so zemiakovou kašou a rukolovým olejom 150g/200g",
              "price": "",
            },
          },
          Object {
            "dish": Object {
              "dish_id": "688202610",
              "name": "A:7",
              "price": "5,49 €",
            },
          },
          Object {
            "dish": Object {
              "dish_id": "688202611",
              "name": "II. Kurací Cordon Bleu s domácimi americkými zemiakmi a tatárskou omáčkou 130g/200g",
              "price": "",
            },
          },
          Object {
            "dish": Object {
              "dish_id": "688202612",
              "name": "A:1,3,7,10,12",
              "price": "5,99 €",
            },
          },
          Object {
            "dish": Object {
              "dish_id": "688202613",
              "name": "III. Domáce Gnocchi s lososom, cherry rajčinami, baby špenátom a maslovou omáčkou  300g",
              "price": "",
            },
          },
          Object {
            "dish": Object {
              "dish_id": "688202614",
              "name": "A:4,7",
              "price": "6,49 €",
            },
          },
        ],
        "end_date": "2019-01-30 23:59:59",
        "name": "",
        "start_date": "2019-01-30 00:00:00",
      },
    },
  ],
  "status": "success",
}
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so I am trying to put it into flatlist:

App.js
<DailyMenusList itemList= {this.state.dataSource}/>

DailyMenusList.js
const DailyMenusList = ({ itemList }) => (
    <View style= {StylesJS.mainFlatList} >
        <FlatList
            data={itemList}
            renderItem={({item}) =>
            <View style= {{paddingBottom: 20}}>
                <Text style={StylesJS.restaurantHeader}>Mesto: {item.daily_menus.daily_menu.dishes}</Text>
            </View>
            }
            keyExtractor = {(item, index) => index.toString()}
        />
    </View>
);
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i thought that if the response is like that I would get to dishes with
"item.daily_menus.daily_menu.dishes"

but no. it is giving me an error:
"Invariant Violation: Tried to get frame for out of range index NaN"
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I dunno why, google said that I am giving out empty object, but in the console I get whole response.
Then I thought maybe I am parsing it wrong.

But I am not that far ahead in react-native

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Now I tried to change it a little bit (added JSON.stringify(res)):
getDailyMenus(){
        return fetch("https://developers.zomato.com/api/v2.1/dailymenu?res_id=17937272", {
          headers: {
            Accept: "application/json",
            "User-Key": "361c537f66afe2a8a9dc0c03cef9b91f"
          }
        })
            .then((data) => data.json())
                .then((res) => {/*this.setState({dataSource: (res)});*/console.log(JSON.stringify(res))})
                    .catch((err) => {Alert.alert("Error!"); console.log(err);
                ;});
    }

and the console output is:
{"daily_menus":[{"daily_menu":{"daily_menu_id":"20201786","start_date":"2019-01-30 00:00:00","end_date":"2019-01-30 23:59:59","name":"","dishes":[{"dish":{"dish_id":"688202608","name":"Polievka: Kulajda so strúhaným vajíčkom A:","price":"1,90 €"}},{"dish":{"dish_id":"688202609","name":"I. Bravčové Polpette so syrom so zemiakovou kašou a rukolovým olejom 150g/200g","price":""}},{"dish":{"dish_id":"688202610","name":"A:7","price":"5,49 €"}},{"dish":{"dish_id":"688202611","name":"II. Kurací Cordon Bleu s domácimi americkými zemiakmi a tatárskou omáčkou 130g/200g","price":""}},{"dish":{"dish_id":"688202612","name":"A:1,3,7,10,12","price":"5,99 €"}},{"dish":{"dish_id":"688202613","name":"III. Domáce Gnocchi s lososom, cherry rajčinami, baby špenátom a maslovou omáčkou  300g","price":""}},{"dish":{"dish_id":"688202614","name":"A:4,7","price":"6,49 €"}}]}}],"status":"success"}