call swapExactTokensForETH in javascript

Question

I have the following function in JavaScript:

try {
    let tx = await router.connect(receiver).swapExactTokensForETH(
        tokenAmountToSwap,
        0,
        [token.address, await router.WETH()],
        receiver.address,
        Math.floor(Date.now() / 1000) + 60 * 20
    );
    const receipt = await tx.wait();
    console.log('Transaction successful:', receipt);
} catch (error) {
    console.error('Transaction failed:', error);
    console.log('Reverting at:', error.transactionHash);
}

In the transfer function of my contract, it subtracts a fee from the amount, and when I try to swap the remaining value, it returns the 'Uniswap: K' error. Is there any function to solve my problem?"