Could someone explain the numTokensSellToAddToLiquidity function to me and percent

Could someone tell me what this variable does and what is a good number to set it to in terms of percentage of total coin supply?

I asked the question yesterday but my topic was locked. I am unsure what percent to set it at. I googled this for 2 hours and found no response to what is a recommended amount. Last time I set it to 0.0002% and it was spam selling every transaction to add to LP.
If I set it to false, will my LP tax in my contract still work?

uint256 private numTokensSellToAddToLiquidity = ;

Here is the only function it is used in the contract:

function _transfer(
address from,
address to,
uint256 amount
) private {
require(from != address(0), "ERC20: transfer from the zero address");
require(to != address(0), "ERC20: transfer to the zero address");
require(amount > 0, "Transfer amount must be greater than zero");
if(from != owner() && to != owner())
require(amount <= _maxTxAmount, "Transfer amount exceeds the maxTxAmount.");

// is the token balance of this contract address over the min number of
// tokens that we need to initiate a swap + liquidity lock?
// also, don't get caught in a circular liquidity event.
// also, don't swap & liquify if sender is uniswap pair.
uint256 contractTokenBalance = balanceOf(address(this));

if(contractTokenBalance >= _maxTxAmount)
{
contractTokenBalance = _maxTxAmount;
}

bool overMinTokenBalance = contractTokenBalance >= numTokensSellToAddToLiquidity;
if (
overMinTokenBalance &&
!inSwapAndLiquify &&
from != uniswapV2Pair &&
swapAndLiquifyEnabled
) {
contractTokenBalance = numTokensSellToAddToLiquidity;
//add liquidity
swapAndLiquify(contractTokenBalance);
}

//indicates if fee should be deducted from transfer
bool takeFee = true;

//if any account belongs to _isExcludedFromFee account then remove the fee
if(_isExcludedFromFee[from] || _isExcludedFromFee[to]){
takeFee = false;
}

//transfer amount, it will take tax, burn, liquidity fee
_tokenTransfer(from,to,amount,takeFee);
}