Error: secretOrPrivateKey must be an asymmetric key when using ES256

issuer.getPrivateKey() の値と、示されている ES256 オプションを使用して、src/app.ts:151 の呼び出しを再現します。node_modules/jsonwebtoken/sign.js:124 まで失敗を追跡し、その後、sign が受け付けるキー値と verify に渡される値を比較します。サポートされる動作または必要なキー形式が確立され、焦点を絞った回帰テストまたはドキュメントでカバーされれば完了です。

Description

I am unable to sign a jwt by using the private key associated to a Metamask wallet. Ideally I would like to sign a jwt for a verifiable credential by using the private key of the issuer of the credential:

const vcPayload = {
  sub: sub.getDid(),
  nbf: Math.floor(Date.now() / 1000),
  vc: {
    '@context': ['https://www.w3.org/2018/credentials/v1'],
    type: ['VerifiableCredential'],
    credentialSubject: {
      degree: {
        type: 'BachelorDegree',
        name: 'Baccalauréat en musiques numériques'
      }
    }
  }
}

const vcJwt = jwt.sign(vcPayload, issuer.getPrivateKey(), { algorithm: 'ES256' });

const decodedJwt = jwt.decode(vcJwt, { complete: true });
console.log(`Decoded VC: ${JSON.stringify(decodedJwt)}`);

const verifiedJwt = jwt.verify(vcJwt, issuer.getPublicKey(), { algorithms: ['ES256'] });
console.log(`Verified VC: ${JSON.stringify(JSON.stringify(verifiedJwt))}`);

The problem I am encountering is the following one:

Error: secretOrPrivateKey must be an asymmetric key when using ES256
    at module.exports [as sign] (node_modules/jsonwebtoken/sign.js:124:22)
    at main (src/app.ts:151:21)
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5) {stack: 'Error: secretOrPrivateKey must be an asymmetr…ions (node:internal/process/task_queues:95:5)', message: 'secretOrPrivateKey must be an asymmetric key when using ES256'}

Environment

"jsonwebtoken": "9.0.0"