wallet-adapter

    abstract sendTransaction(        transaction: TransactionOrVersionedTransaction<this['supportedTransactionVersions']>,        connection: Connection,        options?: SendTransactionOptions    ): Promise<TransactionSignature>;     protected async prepareTransaction(        transaction: Transaction,        connection: Connection,        options: SendOptions = {}    ): Promise<Transaction> {        const publicKey = this.publicKey;        if (!publicKey) throw new WalletNotConnectedError();         transaction.feePayer = transaction.feePayer || publicKey;        transaction.recentBlockhash =            transaction.recentBlockhash ||            (                await connection.getLatestBlockhash({                    commitment: options.preflightCommitment,                    minContextSlot: options.minContextSlot,                })            ).blockhash;

1. Line 97 abstract sendTransaction(: Submits the signed transaction to the cluster.
2. Line 115 await connection.getLatestBlockhash({: Fetches a recent blockhash. Transactions expire if it gets too old.

import { Button } from '@mui/material';import { useConnection, useWallet } from '@solana/wallet-adapter-react';import type { TransactionSignature } from '@solana/web3.js';import { PublicKey, Transaction, TransactionInstruction } from '@solana/web3.js';import React, { useCallback, type FC } from 'react';import { useNotify } from './useNotify'; export const SendTransaction: FC = () => {    const { connection } = useConnection();    const { publicKey, sendTransaction } = useWallet();    const notify = useNotify();     const onClick = useCallback(async () => {        let signature: TransactionSignature | undefined = undefined;        try {            if (!publicKey) throw new Error('Wallet not connected!');             const {                context: { slot: minContextSlot },                value: { blockhash, lastValidBlockHeight },            } = await connection.getLatestBlockhashAndContext();             const transaction = new Transaction({                feePayer: publicKey,

1. Line 10 const { publicKey, sendTransaction } = useWallet();: Submits the signed transaction to the cluster.
2. Line 21 } = await connection.getLatestBlockhashAndContext();: Fetches a recent blockhash. Transactions expire if it gets too old.

            } = await connection.getLatestBlockhashAndContext();             const message = new TransactionMessage({                payerKey: publicKey,                recentBlockhash: blockhash,                instructions: [                    {                        data: Buffer.from('Hello, from the Solana Wallet Adapter example app!'),                        keys: [],                        programId: new PublicKey('MemoSq4gqABAXKb96qnH8TysNcWxMyWCqXgDLGmfcHr'),                    },                ],            });            const transaction = new VersionedTransaction(message.compileToLegacyMessage());             signature = await sendTransaction(transaction, connection, { minContextSlot });            notify('info', 'Transaction sent:', signature);             await connection.confirmTransaction({ blockhash, lastValidBlockHeight, signature });            notify('success', 'Transaction successful!', signature);        } catch (error: any) {            notify('error', `Transaction failed! ${error?.message}`, signature);        }    }, [publicKey, supportedTransactionVersions, connection, sendTransaction, notify]);

1. Line 25 } = await connection.getLatestBlockhashAndContext();: Fetches a recent blockhash. Transactions expire if it gets too old.
2. Line 40 signature = await sendTransaction(transaction, connection, { minContextSlot });: Submits the signed transaction to the cluster.