pages/js/auth.js

const authCode = new URL(document.location).searchParams.get('code')

if(typeof authCode !== undefined) {
  fetch('https://crss-api.theclashfruit.workers.dev/login', {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json'
    },
    body: JSON.stringify({ authCode: authCode })
  })
    .then(res => res.json())
    .then(res => {
      localStorage.setItem('token', res.access_token)
      localStorage.setItem('refresh', res.refresh_token)
    })
}