bitcoinjs-lib: Newbie here, need some help, stuck on psbt transaction creation and signing

Didn’t have problem with the output, but when processing input, kept showing “Error: Data for input key witness Utxo is incorrect: Expected {script: Buffer; Value: number}” and got …". The problem is, I already got the appropriate format there.

Also, when signing, though with the proper private key, it kept popping “No transactions were signed” errors.

the input is a 2 of 3 multisig input

Please help, thanks

Here’s my code for transaction creation

var p = 'https://api.smartbit.com.au/v1/blockchain/address/'+addr;
const resp = await fetch(p);
const r = await resp.json();
var tx = new bitcoin.Psbt({
  network: bitcoin.networks.bitcoin
});
var amount = r.address.confirmed.balance_int;
for(var j = 0; j < r.address.transactions.length; j++) {
  var scriptpubkey='';
  for (var k = 0; k < r.address.transactions[j].output_count; k++) {
    if (r.address.transactions[j].outputs[k].addresses[0]==addr) {
      scriptpubkey=r.address.transactions[j].outputs[k].script_pub_key.hex;
    }
  }
  await tx.addInput({
    hash: r.address.transactions[j].hash,
    index: j,
    witnessUtxo: {
      script: Buffer.from(scriptpubkey, 'hex'),
      value: r.address.transactions[j].output_amount_int,
    },
  });
  var tx_receiver=await txr.toHex();
}

Here’s the code for signing

sign = function (message, key) {
  var psbt = bitcoin.Psbt.fromHex(message);
  var keyPair = bitcoin.ECPair.fromWIF(key);
  psbt.signAllInputs(keyPair);
  return psbt.toHex();
}