Problem with API of Twitch with Axios GET POST

i got problem with codes.

axios({
        method: 'post',
        url: 'https://id.twitch.tv/oauth2/token',
        body: {
        client_id: 'a',
        client_secret: 'Bearer b',
        grant_type: 'client_credentials',}
            }).then(response => {
        console.log(response);

      })
      .catch(error => {
        console.log(error);
      })

and result is :

data: { status: 400, message: 'missing client id' }

but this way works fine if i put them in url :

url: 'https://id.twitch.tv/oauth2/token?client_id=a&client_secret=b&grant_type=client_credentials',

what is my problem? also can u give me an example for axios.get ? with :

url: 'https://api.twitch.tv/helix/games/top'
headers: {
client_id: 'a',
Authorization: 'Bearer b',
}

For axios you need to be sending as data not body

And then construct/send a FormData

So for example

axios({
  method: "post",
  url: "myurl",
  data: bodyFormData,
  headers: { "Content-Type": "multipart/form-data" },
})
  .then(function (response) {
    //handle success
    console.log(response);
  })
  .catch(function (response) {
    //handle error
    console.log(response);
  });

See also: axios post request to send form data and: https://github.com/axios/axios/issues/318

Using body will get mixed results as the library (axios) won't know how to encode the data being sent

Personally myself I'm using got over axios so I send

            got({
                url: "https://id.twitch.tv/oauth2/token",
                method: "POST",
                headers: {
                    "Accept": "application/json"
                },
                form: {
                    client_id: config.client_id,
                    client_secret: config.client_secret,
                    grant_type: "client_credentials"
                },
                responseType: "json"
            })
            .then(resp => {
                //SNIP