I've been using the [Steem JavaScript library](https://www.npmjs.com/package/steem), and have this code:
```
var steem = require("steem");

const USER = "smitop";
const POSTING_KEY = require("./postingKey.js")

var wif = steem.auth.toWif(USER, POSTING_KEY, 'posting');

steem.broadcast.vote(
    wif, USER, "heavey", "bitcoin-cash-the-new-bitcoin-bitcoin-cash-hard-fork-nov-13th", 1,
    function (err, result) {
    console.log(err, result);
});
```

With my posting key in ```./postingKey.js```.

But, when I run it, I get this error, and a bunch of other stuff:
```
{ Error: 3030000 tx_missing_posting_auth: missing required posting authority
Missing Posting Authority smitop
```

Does anyone know how to fix this?