Working with Social Authentication

// Authorize: GET https://github.com/login/oauth/authorize?client_id=...&scope=user:email&state=...
// Callback receives ?code=...&state=...
const res = await fetch("https://github.com/login/oauth/access_token", {
  method: "POST",
  headers: { "Accept": "application/json", "Content-Type": "application/json" },
  body: JSON.stringify({ client_id, client_secret, code, redirect_uri })
});
const { access_token } = await res.json();
const user = await fetch("https://api.github.com/user", {
  headers: { "Authorization": `Bearer ${access_token}` }
}).then(r => r.json());