Sign a Solana message

signMessage: ({
  message,
  options
}: {
  message: Uint8Array;
  wallet: ConnectedStandardSolanaWallet;
  options?: {
    uiOptions?: SignMessageModalUIOptions;
  };
}) =>
  Promise<{
    signature: Uint8Array;
  }>;

import {useWallets, useSignMessage} from '@privy-io/react-auth/solana';
import bs58 from 'bs58';

const {wallets} = useWallets();
const {signMessage} = useSignMessage();

const selectedWallet = wallets[0];

const message = 'Hello world';
const signatureUint8Array = (
  await signMessage({
    message: new TextEncoder().encode(message),
    wallet: selectedWallet,
    options: {
      uiOptions: {
        title: 'Sign this message'
      }
    }
  })
).signature;
const signature = bs58.encode(signatureUint8Array);