const token = "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpZCI6InVfMTIzNDUiLCJ0ZW5hbnRfaWQiOiJzeXN0ZW0ifQ.XYZ";
const base64Url = token.split('.')[1];
let base64 = base64Url.replace(/-/g, '+').replace(/_/g, '/');
const pad = base64.length % 4;
if (pad) {
  base64 += '='.repeat(4 - pad);
}
const jsonPayload = decodeURIComponent(atob(base64).split('').map(function(c) {
    return '%' + ('00' + c.charCodeAt(0).toString(16)).slice(-2);
}).join(''));
console.log(JSON.parse(jsonPayload));