How to use the node-forge.pki.publicKeyToPem function in node-forge

t.test('should sign a jwt', (assert) => {
    assert.plan(2)
    const keyPair = createKeyPair()
    const jwtPayload = {
      iss: 'SOMETHING',
    }
    const token = signJwt(keyPair.privateKey, jwtPayload)
    assert.ok(token)
    assert.ok(verify(token, pki.publicKeyToPem(keyPair.publicKey)))
  })
})

private generateKeyPair(key: string) {
        const keypair = pki.rsa.generateKeyPair({ bits: 1024 });
        const privateKey = pki.privateKeyToPem(keypair.privateKey);
        const publicKey = pki.publicKeyToPem(keypair.publicKey);
        this.keyPairs[key] = { publicKey, privateKey };
        return publicKey;
    }
}

sendClientKeyExchange () {
    this.sendHandshakeMessage(HandshakeType.CLIENT_KEY_EXCHANGE,
      prepend16(publicEncrypt({
        key: pki.publicKeyToPem(this.serverCertificates[0].publicKey),
        padding: RSA_PKCS1_PADDING
      }, this.preMasterSecret)))
  }

export const generateRsaKeyPems = () => {
  const keyPair = generateRsaKeyPair()
  return {
    publicKey: pki.publicKeyToPem(keyPair.publicKey),
    privateKey: pki.privateKeyToPem(keyPair.privateKey),
  }
}