Sign Starknet transactions

After the account is connected, you can sign a transaction using the wallet.account.signer.signTransaction function:

const signStarknetTransaction = async (wallet, contractAddress, entrypoint, calldata) => {
  try {
    if(wallet?.isConnected !== true){
      throw('Wallet not connected');
    } 
  
    // Send the transaction
    const result = await wallet?.account?.signer.signTransaction({
      contractAddress: contractAddress,  // The address of the contract
      entrypoint: entrypoint,            // The function to call in the contract
      calldata: calldata                 // The parameters to pass to the function
    });
    console.log('Transaction signed successfully:', result);
    return result;
  } catch (error) {
    console.error('Error signing transaction:', error);
  }
};