btc-create-raw-transaction.js

const bitcoin = require('bitcoinjs-lib')
const psbt = new bitcoin.Psbt({ network: bitcoin.networks.testnet })

// example transaction
const unspentOutput = {
  "txid": "11e5b7005a76c8a53f9a0036bc1a2745ebd73ad40017b3169894aa2c19e789d7",
  "vout": 1,
  "address": "2NCxBSjMaVeBFyxmGcD2X428v6k5n3pCQKN",
  "label": "payment",
  "redeemScript": "001495a994a417c45f97c87d03efb21997452d4c782f",
  "scriptPubKey": "a914d82952189f437226406ec17c8c397a34af177cd187",
  "amount": 1.00000000,
  "confirmations": 24,
  "spendable": true,
  "solvable": true,
  "desc": "sh(wpkh([7fc5659a/0'/0'/1']02284916d8cd4fdf35574d5f0aaea0c93607254b06601ef126e73d8fb075b7169f))#6k9sssw6",
  "safe": true
}

// get transaction hex and check if it's a Segwit or Non-Segwit transaction
const rawTransaction = getRawHex(unspentOutput.txid) // you can use `gettransaction` rpc to get the transaction hex

if (isSegwit) {
  // add segwit transaction input
 
  psbt.addInput({
    hash: unspentOutput.txid,
    index: unspentOutput.vout,
    witnessUtxo: {
      script: Buffer.from(unspentOutput.scriptPubKey, 'hex'),
      value: unspentOutput.amount * 100000000 // value in satoshi
    },
    redeemScript: Buffer.from(unspentOutput.redeemScript, 'hex')
  })
} else {
  // add non-segwit transaction input

  psbt.addInput({
    hash: unspentOutput.txid,
    index: unspentOutput.vout,
    nonWitnessUtxo: Buffer.from(rawTransaction, 'hex'),
    redeemScript: Buffer.from(unspentOutput.redeemScript, 'hex')
  })
}

// add output - destination address and the amount to transfer to

psbt.addOutput({
  address: '2NF3WNhdXJzgChaAZgdYjHWaAvYG25Nhz58',
  value: 50000000 // value is satoshi (0.5 BTC)
})

// We have input of 1 BTC and we are trying to send 0.5 BTC
// If we just use these configurations to send the transaction, it will consume remaining 0.5 BTC as fees
// which you wouldn't want
// So leave some fee for the transaction, let's say 0.001 BTC and send the remaining amount to change address
// change address is the address you own where change from the transaction can be sent to


psbt.addOutput({
  address: '2MzaZzn4cuAByJrNRpDHEgE8Z55Y7dsi3Gq', // change address
  value: 49900000 // value is satoshi (0.499 BTC)
})

// create transaction end

// check if it's a Segwit or Non-Segwit transaction
const isSegwit = rawTransaction.substring(8, 12) === '0001'

before conditional check of the segwit