const api = await ApiPromise.create();
// Construct the keyring after the API (crypto has an async init)
const keyring = new Keyring({ type: 'sr25519' });
// Replace //Alice with your mnemonic phrase
const keypair = keyring.addFromUri('//Alice');
const extrinsic = api.tx.network.claimStakeUnbondings();
const hash = await extrinsic.signAndSend(keypair);