C:\Users\RayRay\Desktop\Alpha\RPC>node .
(node:5628) UnhandledPromiseRejectionWarning: Error: OAuth2 Authorization Error: Unknown Error
    at RPCClient._onRpcMessage (C:\Users\RayRay\Desktop\Alpha\RPC\node_modules\discord-rpc\src\client.js:185:19)
    at IPCTransport.emit (events.js:311:20)
    at C:\Users\RayRay\Desktop\Alpha\RPC\node_modules\discord-rpc\src\transports\ipc.js:134:18
    at decode (C:\Users\RayRay\Desktop\Alpha\RPC\node_modules\discord-rpc\src\transports\ipc.js:92:5)
    at Socket.<anonymous> (C:\Users\RayRay\Desktop\Alpha\RPC\node_modules\discord-rpc\src\transports\ipc.js:120:7)
    at Socket.emit (events.js:311:20)
    at emitReadable_ (_stream_readable.js:562:12)
    at processTicksAndRejections (internal/process/task_queues.js:83:21)
(node:5628) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To te
rminate the node process on unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 1)
(node:5628) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

Code:

const clientId = '[CENSORED]]';
const scopes = ['rpc', 'rpc.api', 'messages.read'];

const RPC = require('discord-rpc')

const client = new RPC.Client({ transport: 'ipc' });

client.on('ready', () => {
    console.log('Logged in as', client.application.name);
    console.log('Authed for user', client.user.username);

    client.selectVoiceChannel('81384788862181376');
});

// Log in to RPC with client id
client.login({ clientId, scopes });