lazor-kit

      // too large, nothing has been sent — sign again.      const migrateInstructions = plan.migrate.finalize(response);      if (txBytes(migrateInstructions) > MAX_TX_BYTES) {        throw new Error(          'Your browser made that signature a little larger than usual, and the move no longer ' +            'fits in one transaction. Nothing was sent — press Move again.',        );      }       const signatures: string[] = [];      const send = async (instructions: TransactionInstruction[]) => {        const { blockhash: recent } = await connection.getLatestBlockhash();        const message = new TransactionMessage({          payerKey: payer,          recentBlockhash: recent,          instructions,        }).compileToV0Message();        const tx = new VersionedTransaction(message);        let signature: string;        if (local) {          tx.sign([local]);          signature = await connection.sendTransaction(tx);        } else {          signature = await paymaster.signAndSendVersionedTransaction(tx);

1. Line 408 const { blockhash: recent } = await connection.getLatestBlockhash();: Fetches a recent blockhash. Transactions expire if it gets too old.
2. Line 418 signature = await connection.sendTransaction(tx);: Submits the signed transaction to the cluster.