Using this sendBNB function you can send BNB from one walletAddress to another walletAddress:

wallet_addressStringThe address for the sending account (sender's address).
wallet_passwordStringThe password which you set up already for your wallet.
gas_priceBigIntegerThe price of gas for this transaction fee.
gas_limitBigIntegerThe amount of gas to use for the transaction.
bnb_amountBigDecimalThe amount of BNB you wish to send to the destination address.
receiver_wallet_addressStringThe destination wallet address (receiver's address).
BinanceManager binanceManager = BinanceManager.getInstance();
String walletAddress = "{{wallet_address}}";
String password = "{{wallet_password}}";
BigInteger gasPrice = new BigInteger("{{gas_price}}");
BigInteger gasLimit = new BigInteger("{{gas_limit}}");
BigDecimal bnbAmount = new BigDecimal("bnb_amount");
String receiverAddress = "receiver_wallet_address";
binanceManager.sendBNB(walletAddress, password,gasPrice,gasLimit,bnbAmount, receiverAddress, this)
                .subscribe(tx -> {

                    Toast.makeText(this, "TX : " + tx, Toast.LENGTH_SHORT).show();

                }, error -> {