If I did not get a refund on my 2020 taxes and had to pay, will my 3rd stimulus check be mailed to me since my direct deposit information was only on my 2019 taxes?

It depends on what IRS considers to be the best resource below.

Here is what IRS is saying on their site:

The IRS has indicated they’re using the latest taxpayer information they have on file to issue the third stimulus payment. That means they are sending your stimulus payment to one of the following:

• Bank account information from the direct deposit of your 2019 or 2020 tax refund,
• Bank account information you entered on your non-filer registration in 2020,
• Bank account information you entered on Get My Payment before December 22, 2020, or
• Banking information used by a federal agency that provides you benefits such as the Social Security Administration, Veteran Affairs, or the Railroad Retirement Board.

If you didn’t update your information with the IRS, they will issue your payment using the latest information they have in your file, not the information you provided to the TurboTax portal.