you may not need to. there are no penalties for underestimation of estimated taxes if any of the following apply:
1) withholding and timely estimated tax payments = 90% of 2020 tax
2) or 100% 2019 tax (110% if your 2019 adjusted gross income was over $150,000)
if you don't meet any of these exceptions you can pay in more now but you'll still have some underestimation penalty because you are paying after 1/15/2021
