useSignTransactionBlock

import { ConnectButton, useCurrentAccount, useSignTransactionBlock } from '@mysten/dapp-kit';
import { useState } from 'react';
 
function MyComponent() {
	const { mutate: signTransactionBlock } = useSignTransactionBlock();
	const [signature, setSignature] = useState('');
	const currentAccount = useCurrentAccount();
 
	return (
		<div style={{ padding: 20 }}>
			<ConnectButton />
			{currentAccount && (
				<>
					<div>
						<button
							onClick={() => {
								signTransactionBlock(
									{
										transactionBlock: new TransactionBlock(),
										chain: 'sui:devnet',
									},
									{
										onSuccess: (result) => {
											console.log('signed transaction block', result);
											setSignature(result.signature);
										},
									},
								);
							}}
						>
							Sign empty transaction block
						</button>
					</div>
					<div>Signature: {signature}</div>
				</>
			)}
		</div>
	);
}