If you withdraw the money in 2020, then by the time you file your 2020 tax return (March or April 2021 for most of us), you have to be square with the government.
Square here would be that the difference between the total tax as calculated on your form and the total money you have given to the government has to be 0. The total money you have given to the government is the sum of money withheld by various entities (i.e. your employer) and any additional payments you have made, usually known as estimated tax payments.
I chose the phrasing above, because almost surely, when you attempt to withdraw money from your 401(k) plan, the entity that administers that plan will withhold a good portion of it for these various taxes and penalties. You will probably need to tell them your tax rate, plus they will withhold the % appropriate to the penalties for early withdraw.
If your plan administrator does not do that withholding for you, then because the US tax system is a pay-as-you-go system, you will be expected to make an estimated tax payment and pay in the aforementioned income taxes and early withdraw penalties in the quarter you took the money out. If you do not make that payment, the government may assess you a penalty for not paying-as-you-go on top of all the other taxes and penalties. There is a chance you may qualify for a safe-harbor waiver of those non-pay-as-you-go penalties, but it gets complicated pretty quick. Almost surely better to make this payment yourself if your plan administrator does not take it out for you.