how to use the javascript fetch api to get data

1fetch('https://api.github.com/users/manishmshiva', {
2  method: "GET",
3  headers: {"Content-type": "application/json;charset=UTF-8"}
4})
5.then(response => response.json()) 
6.then(json => console.log(json)); 
7.catch(err => console.log(err));

1fetch('http://api.steampowered.com/ISteamUserStats/GetGlobalAchievementPercentagesForApp/v0002/?gameid=221380')
2    .then(function(response) {
3        return response.json();
4    })
5    .then(function(myJson) {
6        console.log(JSON.stringify(myJson));
7    });
8

1const GetData = [];
2  useEffect(() => {
3    fetch(API_URL)
4      .then((res) => res.json())
5      .then((data) => {
6        GetModesData.push(...data);
7        setDataState(GetData.map((d) => d.modeName));
8      });
9  }, []);
10

1const GetData = [];
2  useEffect(() => {
3    fetch(API_URL)
4      .then((res) => res.json())
5      .then((data) => {
6        GetModesData.push(...data);
7        setDataState(GetData.map((d) => d.modeName));
8      });
9  }, []);

1.catch(function() {
2
3});