Axios and POST request to Zendesk API

I'm trying a custom ticket form with the Zendesk API for end users. I followed this tutorial but it uses Python whereas I use Node and React. I use Axios but I got an error response

data: { error: "Couldn't authenticate you" }

Here is my code

    var axios = require('axios');
    var config = {
      method: 'post',
      url:'https://subdomain.zendesk.com/api/v2/requests.json',
      headers: { 
        'content-type': 'application/json'
      },
      data:{'request':{'subject': 'test', 'comment': {'body': 'ceci est un test'}}},
      auth:('MY_EMAIL/token:_TOKEN'),
    };
    
    axios(config)
    .then(function (response) {
      res.send(response.data);
    })
    .catch(function (error) {
      console.log(error);
    });

You should set your token as header like so:

var axios = require('axios');

const token = '{base-64-encoded email_address/token:api_token}'

var config = {
  method: 'post',
  url:'https://subdomain.zendesk.com/api/v2/requests.json',
  headers: { 
    'content-type': 'application/json',
    'Authorization': `Basic ${token}` 
  },
  data:{'request':{'subject': 'test', 'comment': {'body': 'ceci est un test'}}}
};

axios(config)
.then(function (response) {
  res.send(response.data);
})
.catch(function (error) {
  console.log(error);
});