Issue with staking via wallet adapter

Question

Need to create stake account and then delegate via wallet-adapter in NextJS. Took some code from Solana Cookbook. Getting an issue after accepting transaction in any wallet, crashes at the line sendTransaction() with WalletSendTransactionError: 400 : {"error":"Request failed with status code 502"}

Also would appreciate if somebody explains what nonceAccount and minContextSlot is, still can't get it.

  const handleStake = async () => {
if (!publicKey || !wallet) return;
const stakeAccount = new Keypair();

const minimumRent = await connection.getMinimumBalanceForRentExemption(
  StakeProgram.space
);
const amountUserWantsToStake = LAMPORTS_PER_SOL / 2; // This is can be user input. For now, we'll hardcode to 0.5 SOL
const amountToStake = minimumRent + amountUserWantsToStake;

const transaction = new Transaction().add(
  StakeProgram.createAccount({
    fromPubkey: publicKey,
    stakePubkey: stakeAccount.publicKey,
    lamports: amountToStake,
    lockup: new Lockup(0, 0, publicKey),
    authorized: new Authorized(publicKey, publicKey),
  })
);

const signature = await sendTransaction(transaction, connection);

const strategy: TransactionConfirmationStrategy = {
  signature: signature,
  nonceAccountPubkey: publicKey,
  minContextSlot: transaction.lastValidBlockHeight!,
  nonceValue: transaction.nonceInfo!.nonce,
};

await connection.confirmTransaction(strategy, "processed");

// Check our newly created stake account balance. This should be 0.5 SOL.
let stakeBalance = await connection.getBalance(stakeAccount.publicKey);
console.log(
  `Stake account balance: ${stakeBalance / LAMPORTS_PER_SOL} SOL`
);

// Verify the status of our stake account. This will start as inactive and will take some time to activate.
let stakeStatus = await connection.getStakeActivation(
  stakeAccount.publicKey
);
console.log(`Stake account status: ${stakeStatus.state}`);

};

Answer 1

const stakeAccount = new Keypair();

const signature = await sendTransaction(transaction, connection, {
  signers: [stakeAccount],
});

Try catch could help to dive in to RPC errors.