signTransaction and getTransaction on blockchain Golos on HTML

sign_and_send_transaction.html

<script src="https://wzrd.in/standalone/buffer"></script>
<script src="https://momentjs.com/downloads/moment.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/golos-js@0.5.30/dist/golos.min.js"></script>
<script>
// switch to testnet
golos.config.set('websocket', 'wss://ws.testnet3.golos.io');
golos.config.set('chain_id', '5876894a41e6361bde2e73278f07340f2eb8b41c2facd29099de9deef6cdb679');

// private posting key
let wif = '5J...';

// https://github.com/GolosChain/golos-js/blob/master/doc/README.md#vote
let operations = [
	// vote operation
	['vote', {
	// params for vote operation
		'author': 'golos-test',
		'permlink': '7apsm1-qwerty',
		'voter': 'test',
		'weight': 10000
	}]
];

// https://github.com/GolosChain/golos-js/blob/master/doc/README.md#get-dynamic-global-properties
golos.api.getDynamicGlobalProperties(function(err, properties) {
	console.log(err, 'getDynamicGlobalProperties: ', properties);
	
	// https://github.com/GolosChain/golos-js/blob/master/doc/README.md#get-block
	golos.api.getBlock(properties.head_block_number - 2, function(err, block) {
		console.log(err, 'getBlock: ', block);
		
		let trx = {
			ref_block_num: (properties.head_block_number - 3) & 0xFFFF,
			ref_block_prefix: buffer.Buffer(block.previous, 'hex').readUInt32LE(4),
			expiration: moment(properties.time).add(1, 'hours').format('YYYY-MM-DDTHH:mm:ss'), // 2018-03-07T18:10:21
			operations: operations,
			signatures: [],
		};
		
		let keys = {
			posting: wif
		};
		// https://github.com/GolosChain/golos-js/blob/master/doc/README.md#sign-transaction
		trx = golos.auth.signTransaction(trx, keys);
		console.log('signTransaction: ', trx);
		
		// https://github.com/GolosChain/golos-js/blob/master/doc/README.md#get-transaction-hex
		golos.api.getTransactionHex(trx, function(err, result) {
			console.log(err, 'getTransactionHex: ' + result);
		});
		
		// https://github.com/GolosChain/golos-js/blob/master/doc/README.md#broadcast-transaction-synchronous
		golos.api.broadcastTransactionSynchronous(trx, function(err, trxData) {
			console.log(err, 'broadcastTransactionSynchronous: ', trxData);
			
			// https://github.com/GolosChain/golos-js/blob/master/doc/README.md#get-transaction
			golos.api.getTransaction(trxData.id, function(err, result) {
				console.log(err, 'getTransaction: ', result);
			});
			
		});
		
	});
	
});
</script>