Unable to update Data - rest

Question

Am trying to update the json data through an api call.
I was able to GET the data without any issues, as am not passing any Options in the request.
For UPDATE,
//saga.js
export function* BlurideaTitler(opt) {
const id = opt.id; // 4
const updatedTitle = opt.newTitle; // "title changed"
let options = {
crossDomain: true,
method: 'PUT',
json: true,
headers: {'Content-Type': 'application/json'},
body: {
title: updatedTitle
}
};
const requestURL = `http://localhost:3000/ideas/${id}`;
try {
yield call(request, requestURL, options);
} catch (err) {
console.log(err);
}
}
// request.js
export default function request(url, options) {
return fetch(url, options)
.then(checkStatus)
.then(parseJSON);
}
//db.json
JSON am trying to update.,
{
"ideas": [
{
"id": 4,
"title": "My fourth Idea",
"body": "Description of my fourth idea",
"created_date": "14-Apr-2019"
}
]
}
This is supposed to update the value of title. But it throws error'Bad request' . Can someone please let me know what am missing here.