Service worker get config from outside

index.js

if ('serviceWorker' in navigator) {
  navigator.serviceWorker
    .register('./sw.js')
    .then(function(registration) {
      const interval = setInterval(() => {
        try {
          registration.installing.postMessage({
            'api.github.com/users/monkindey': {}
	  });
        } catch (err) {
          clearInterval(interval);
        }
      }, 500);
      console.log('Service worker registration succeeded:', registration);
    })
    .catch(function(error) {
      console.log('Service worker registration failed:', error);
    });
} else {
  console.log('Service workers are not supported.');
}

axios.get('https://api.github.com/users/monkindey').then(res => {
  console.log(res);
});

window.onload = () => {
  axios.get('https://api.github.com/users/monkindey').then(res => {
    console.log(res);
  });
};

sw.js

let fetchings = null;

const installPromise = new Promise(function(resolve, reject) {
  self.addEventListener('message', function(event) {
    fetchings = event.data;
    resolve();
  });
});

self.addEventListener('install', event => {
  console.log('install');
  event.waitUntil(installPromise);
});

self.addEventListener('fetch', event => {
  console.log(fetchings, event.request.url);
});