How to use the @polkadot/keyring.Keyring function in @polkadot/keyring

async function main() {
    // Construct

    const wsProvider = new WsProvider('ws://127.0.0.1:8546');
    const api = await ApiPromise.create({ provider: wsProvider });

    // Simple transaction
    const keyring = new Keyring({type: 'sr25519' });
    const aliceKey = keyring.addFromUri('//Alice',  { name: 'Alice default' });
    console.log(`${aliceKey.meta.name}: has address ${aliceKey.address} with publicKey [${aliceKey.publicKey}]`);

    const ADDR_Bob = '0x90b5ab205c6974c9ea841be688864633dc9ca8a357843eeacf2314649965fe22';

    const transfer = await api.tx.balances.transfer(ADDR_Bob, 12345)
        .signAndSend(aliceKey, {era: 0, blockHash: '0x64597c55a052d484d9ff357266be326f62573bb4fbdbb3cd49f219396fcebf78', blockNumber:0,  genesisHash: '0x64597c55a052d484d9ff357266be326f62573bb4fbdbb3cd49f219396fcebf78', nonce: 1, tip: 0, transactionVersion: 1});

    console.log(`hxHash ${transfer}`);

}

async function main () {
  // Instantiate the API
  const api = await ApiRx.create().toPromise();

  // Create an instance of the keyring
  const keyring = new Keyring({ type: 'sr25519' });

  // Add Alice to our keyring (with the known seed for the account)
  const alice = keyring.addFromUri('//Alice');

  // Create a extrinsic, transferring 12345 units to Bob.
  const subscription = api.tx.balances
    // create transfer
    .transfer(BOB, 12345)
    // Sign and send the transcation
    .signAndSend(alice)
    // Subscribe to the status updates of the transfer
    .subscribe(({ status }) => {
      if (status.isFinalized) {
        console.log(`Successful transfer of 12345 from Alice to Bob with hash ${status.asFinalized.toHex()}`);
        subscription.unsubscribe();
      } else {

async function main () {
  // Instantiate the API
  const api = await ApiPromise.create();

  // Constuct the keying after the API (crypto has an async init)
  const keyring = new Keyring({ type: 'sr25519' });

  // Add Alice to our keyring with a hard-deived path (empty phrase, so uses dev)
  const alice = keyring.addFromUri('//Alice');

  // Create a extrinsic, transferring 12345 units to Bob
  const transfer = api.tx.balances.transfer(BOB, 12345);

  // Sign and send the transaction using our account
  const hash = await transfer.signAndSend(alice);

  console.log('Transfer sent with hash', hash.toHex());
}

async function main () {
  // Instantiate the API
  const api = await ApiPromise.create(); // default provider

  // Constuct the keying after the API (crypto has an async init)
  const keyring = new Keyring({ type: 'sr25519' });

  // Add Alice to our keyring with a hard-derived path (empty phrase, so uses dev)
  const alice = keyring.addFromUri('//Alice');

  // Get nonce for account
  const nonce = await api.query.system.accountNonce(alice.address);

  // Get current block
  const signedBlock = await api.rpc.chain.getBlock();

  // Get current block height and hash
  const currentHeight = signedBlock.block.header.number;
  const blockHash = signedBlock.block.header.hash;

  // NOTE By default the API will send mortal transactions, only explicitly construct
  // if you wish to override the defaults

export default async function cmdSign (account: string, seed: string, type: Curves, [payload]: string[]): Promise {
  await cryptoWaitReady();

  const keyring = new Keyring({ type });
  const pair = keyring.createFromUri(seed);
  const signature = pair.sign(hexToU8a(payload));

  const prefix = new Uint8Array(curvePrefixes[type]);

  console.log(`Signature: ${u8aToHex(u8aConcat(prefix, signature))}`);

  process.exit(0);
}

async function makeTx ({ fn, log }: CallInfo): Promise {
  assert(seed, 'You need to specify an account seed with tx.*');
  assert(CRYPTO.includes(sign), `The crypto type can only be one of ${CRYPTO.join(', ')} found '${sign}'`);

  const keyring = new Keyring();
  const account = keyring.createFromUri(seed, {}, sign as 'ed25519');

  return fn(...params).signAndSend(account, (result: SubmittableResult): void => {
    log(result);

    if (result.isFinalized) {
      process.exit(0);
    }
  });
}