SyntaxError: Unexpected token o in JSON at position 1

Hello,

I seem to be getting error everytime and now I struck.

Here is my Node implementation of same validation:

let key = process.env.COINBASE_CALLBACK_SECRET;
let payload = {
"id": 1,
"scheduled_for": "2017-01-31T20:50:02Z",
"event": {
"id": "24934862-d980-46cb-9402-43c81b0cdba6",
...
}
}
}
=======================================
Code below
=======================================
function validate(payload, key){
let msg = JSON.parse(payload);
let hash = crypto.createHmac('sha256', key).update(msg);
// convert to hexits from binary
hash.digest('hex');
}

Kindly assist. Thanks.