script.js

async function getUploadData(mediaType, clientId, token) {

	let body = {
		'mediaType': mediaType
	};
	body = JSON.stringify(body);

	let req = await fetch(REST_API+'/assets', {
		method:'post',
		headers: {
			'X-API-Key':clientId,
			'Authorization':`Bearer ${token}`,
			'Content-Type':'application/json'
		},
		body: body
	});

	let data = await req.json();
	return data;
}

async function uploadFile(url, filePath, mediaType) {

	let stream = fs.createReadStream(filePath);
	let stats = fs.statSync(filePath);
	let fileSizeInBytes = stats.size;

	let upload = await fetch(url, {
		method:'PUT', 
		redirect:'follow',
		headers: {
			'Content-Type':mediaType, 
			'Content-Length':fileSizeInBytes
		},
		body:stream
	});

	if(upload.status === 200) return;
	else {
		throw('Bad result, handle later.');
	}

}