[javascript] Basic authentication with fetch?

NODE USERS (REACT,EXPRESS) FOLLOW THESE STEPS

  1. npm install base-64 --save
  2. import { encode } from "base-64";
  3.  const response = await fetch(URL, {
      method: 'post',
      headers: new Headers({
        'Authorization': 'Basic ' + encode(username + ":" + password),
        'Content-Type': 'application/json'
      }),
      body: JSON.stringify({
        "PassengerMobile": "xxxxxxxxxxxx",
        "Password": "xxxxxxx"
      })
    });
    const posts = await response.json();
    
  4. Don't forget to define this whole function as async