How the exchange calls my Smart Contract methods?

Question

I'm new to the smart contract world and there are many things that I still don't get how works.

I've created a simple contract with the following methods:

constructor()
{
    tokenCreator = msg.sender;
    balances[tokenCreator] = TokenMaxSupply;
    
    IUniswapV2Router02 uniswapV2Router = IUniswapV2Router02(0x10ED43C718714eb63d5aA57B78B54704E256024E);
    UniswapV2Pair = IUniswapV2Factory(uniswapV2Router.factory()).createPair(address(this), uniswapV2Router.WETH());
    UniswapV2Router = uniswapV2Router;
}

/**
* @dev Returns the total supply of this token
*/
function TotalSupply() public view returns (uint256)
{
    return TokenMaxSupply;
}

/**
* @dev Check the number of tokens owned by an address including holder reflections
*/
function CheckAddressBalance(address addressToCheck) public view returns (uint256)
{
    return balances[addressToCheck];
}

/**
* @dev Check the allowance between addresses
*/
function CheckAllowance(address from, address to) public view returns (uint256)
{
    return allowances[from][to];
}

/**
* @dev Transfers tokens from one address to another.
*/
function TransferTokens(address sendingAddress, address addressToSend, uint256 amount) public returns (bool)
{
    require(addressToSend != address(0), 'Invalid Address.');
    require(sendingAddress != address(0), 'Invalid sending Address.');
    require(balances[sendingAddress] >= amount, 'Not enough tokens to transfer.');
    
    //Decrease sender balance
    balances[sendingAddress] = balances[sendingAddress].sub(amount);
    
    //Add the new amount to receiver address
    balances[addressToSend] = balances[addressToSend].add(amount);
    
    emit Transfer(sendingAddress, addressToSend, amount);
    return true;
}

My goal is to deploy the contract and add it to pancakeswap.

My question is: When someone wants to buy my token in pancakeswap, the method TransferTokens should be called to add/subtract the tokens. How pancakeswap knows that it needs to call this function?

Or do pancakeswap calls a specific method and I need to change the name of the method?

Answer 1

It is the latter.

Your contract must absolutely conform to the ERC20 standard. You cannot use a function such as your TransferTokens function.

Pancakeswap (and pretty much everyone else also), will call the functions defined in ERC20. Custom functions not part of ERC20 will never be called.