I was using node-fetch before and data was undefined, now I switched to axios and it works out of a sudden. Thanks 
axios
.get("https://api.twitch.tv/helix/users?login=Kozie1337", {
headers: {
"Client-Id": clientid,
Authorization: "Bearer " + token,
},
})
.then((res) => {
console.log(res.data);
});