there is simple source code in HTML and JS about button to connecting wallet as a web3 and loading ETH transaction in Metamask.
javascript
const ethereumButton = document.querySelector('.enableEthereumButton');
const sendEthButton = document.querySelector('.sendEthButton');
let accounts = [];
//Sending Ethereum to an address
sendEthButton.addEventListener('click', () => {
  ethereum
    .request({
      method: 'eth_sendTransaction',
      params: [
        {
          from: accounts[0],
          to: '0x2f318C334780961FB129D2a6c30D0763d9a5C970',
          value: '0x29a2241af62c0000',
          gasPrice: '0x09184e72a000',
          gas: '0x2710',
        },
      ],
    })
    .then((txHash) => console.log(txHash))
    .catch((error) => console.error);
});
ethereumButton.addEventListener('click', () => {
  getAccount();
});
async function getAccount() {
  accounts = await ethereum.request({ method: 'eth_requestAccounts' });
}
HTML
<button class="enableEthereumButton btn">Enable Ethereum</button>
<button class="sendEthButton btn">Send Eth</button>
I would like to ask, how to change code to determine loading of Binance smart chain network (BEP-20) instead of ETH. I tried to find and change ETH contract which would be changed to BEP-20 contract but I don´t see contract there.
Second problem there is that this code contains value of 3 ETH which are loaded for transaction.
I would like to ask where is value set up to 3?