JSFiddle - React, Tailwind, and code Playground

HTML

<!-- WORK WITH THIS VERSION -->
<script src="https://unpkg.com/axios@0.18.0/dist/axios.min.js"></script>

<!-- FAIL WITH THIS VERSION -->

<script>

  
  axios.interceptors.request.use((config) => {
    console.log(config.isBackground)
    return config
  }, (error) => {
    console.log(error.config.isBackground)
    return Promise.reject(error)
  })

  axios.interceptors.response.use((response) => {
    console.log(response.config.isBackground)
    return response
  }, function(error) {
    console.log(error.config.isBackground)
    return Promise.reject(error)
  })

	const config = {
  	isBackground: true
  }
  
	axios.get('https://httpbin.org/get', config)
  	.then(response => {
    	console.log(response)
    })
    .catch(error => {
    	console.log(error)
    })
    
  axios.get('https://httpbin.org/ge', config)
  	.then(response => {
    	console.log(response)
    })
    .catch(error => {
    	console.log(error)
    })
</script>