underbought.ts

const trade = async () => {
  const params = {
    buyToken: 'UNI',
    sellToken: 'ETH',
    sellAmount: '100000000000000000',

    // same failure with slippage commented out
    slippagePercentage: 0.2,
  }
  const res = await axios.get(`https://api.0x.org/swap/v1/quote?${qs.stringify(params)}`);

  // Submit proposal on chain
  await ethers.provider.getSigner().sendTransaction(res.data);
}