Executing Magic Eden Buy: Error: Signature Verification Failed

Question

I'm trying to make a buy on Magic Eden but when I try sendAndConfirmTransaction() I got:

Error: Signature Verification Failed

I am calling an API that sent me back the instruction for build the tx.

var status = await buyTx(input
).then((res) =>{
    const tx = solanaWeb3.Transaction.from(Buffer.from(res.data))
    console.log(tx)
    const sig = solanaWeb3.sendAndConfirmTransaction(conn, tx, [accountFromSeed])
    console.log(sig)
})

In the cosole.log(tx) I can see this in signatures making me think yhat is already signed by ME but only need my wallet signature:

Transaction {
  signatures: [
    { signature: null, publicKey: [PublicKey] },
    {
      signature: <Buffer  ... 14 more bytes>,
      publicKey: [PublicKey]
    }
  ],

Answer 1

The solution was to partialSign the tx and I was able to sign it without problems.

var status = await BuyTx(input
).then((res) =>{
  const tx = solanaWeb3.Transaction.from(Buffer.from(res.createBuyTx.data));
  tx.partialSign(accountFromSeed);
  console.log(tx);
})