sign-payload.js

const crypto = require('crypto');

const { publicKey, privateKey } = crypto.generateKeyPairSync('rsa', {
  modulusLength: 2048,
  publicKeyEncoding: {
    type: 'pkcs1',
    format: 'pem'
  },
  privateKeyEncoding: {
    type: 'pkcs8',
    format: 'pem',
  }
});

const data = { foo: "bar" };

const sign = crypto.createSign('sha256');
sign.update(JSON.stringify(data));
sign.end();

const signature = sign.sign({
  key: privateKey,
  padding: crypto.constants.RSA_PKCS1_PSS_PADDING
}, 'base64');


const isVerified = crypto.verify(
  'sha256',
   Buffer.from(JSON.stringify(data)),
   {
     key: publicKey,
     padding: crypto.constants.RSA_PKCS1_PSS_PADDING,
   },
   Buffer.from(signature, 'base64')
 );

 console.log(isVerified);