Issue assets after certain time

Question

I am following this question answer Trying to implement the answer BUt my transaction is getting failed. Am i doing any mistakes in the implementation part?

  var sendr = Stellar.Keypair.fromSecret('SA43Z6BF57K6SQNN3ZWPSTVZR6QQWVK4ORUJWG5BEBPH4VKFQIQGJ5M3');


  var receivr = 'GAJAG2J2EQ2KUVE5B57JKEKC6WW4G3VEYBXV7FGM2HKZPQ7M5P25HZKW';

   // Create an object to represent the new asset
  var fnew = new Stellar.Asset('FRI', 'GDPSCSBLYQU4TXNPLTDFB2JUIZRQQ5CL2E2NYT5J76MUFEO2CP7S3MMF');

  server.loadAccount(sendr.publicKey())
 .then(function(issuer) {

  var preAuthTx = new Stellar.TransactionBuilder(issuer, opts={fee:1}, issuer.sequence=issuer.sequence+2, timebounds= { minTime: 1560763800})
  .addOperation(Stellar.Operation.payment({
    destination: receivr,
    asset: fnew,
    amount: '20'
}))
  .addOperation(Stellar.Operation.changeTrust({
       asset: fnew,
      limit: '0'
  }))
  .addOperation(Stellar.Operation.accountMerge({
    destination: receivr
}))
.setTimeout(100)
  .build();


  var transaction = new Stellar.TransactionBuilder(issuer, opts={fee:1})
.addOperation(Stellar.Operation.setOptions({
  signer: {
      preAuthTx: preAuthTx.hash(),
      weight: 1
    }
   }))
  .addOperation(Stellar.Operation.setOptions({
masterWeight: 0
  }))


  // setTimeout is required for a transaction
  .setTimeout(100)
  .build();
 transaction.sign(sendr);
  return server.submitTransaction(transaction);
  })
    .then(function(result) {
console.log('Successin sending assets', result);
 })
 .catch(function(error) {
console.error('Error in sending assets', error);
});