How to use the tweetnacl.sign.detached function in tweetnacl

	const signBytes = bytes => sign.detached(bytes, privateKey());

PrivateKey.addSigner(getOID('Ed25519'), function (this: PrivateKey, data: Buffer): Buffer {
  const key = this.keyRaw
  if (key.length !== 64) {
    throw new Error('Invalid signing key.')
  }
  return Buffer.from(ed25519.detached(data, key))
})

  const signBytes = bytes => sign.detached(bytes, key.secretKey);

sign(message, sk, encoding = 'hex') {
    const skBytes = toUint8Array(sk);
    const messageBytes = toUint8Array(message);
    const signature = ed25519.detached(messageBytes, skBytes);
    return encode(signature, encoding);
  }