To set headers in an Axios POST request, pass a third object to the axios.post() call.

You might already be using the second parameter to send data, and if you pass 2 objects after the URL string, the first is the data and the second is the configuration object, where you add a headers property containing another object:

axios.post(url, {
  data: {
    ...
  }
})

axios.post(url, {
  //...data
}, {
  headers: {
    ...
  }
})

To set the authorization header, call it like this:

const token = '..your token..'

axios.post(url, {
  //...data
}, {
  headers: {
    'Authorization': `Basic ${token}` 
  }
})

(the authorization token might differ, check with the app you’re using)

To set headers in an Axios GET request, pass a second object to the axios.get() call, for example this is a GitHub GET request to /user:

axios.get('https://api.github.com/user', {
  headers: {
    'Authorization': `token ${access_token}`
  }
})
.then((res) => {
  console.log(res.data)
})
.catch((error) => {
  console.error(error)
})

I was doing some work with the WordPress API, and I had to authenticate to perform a POST request to a website.

The easiest way for me was to use basic authentication.

I was using Axios, so I set the Authorization header to the POST request in this way:

const username = ''
const password = ''

const token = Buffer.from(`${username}:${password}`, 'utf8').toString('base64')

const url = 'https://...'
const data = {
  ...
}

axios.post(url, data, {
  headers: {
    'Authorization': `Basic ${token}`
  },
})