if you have already paid in 100% of your 2021 tax liability, there are no penalties for late filing or late payment of estimated tax assuming the ones made were timely. if not, then there will be penalties for late payment of estimated tax that stops on 4/18/2022, late filing penalties of 4.5% for up to 5 months after the 4/18 deadline, and a late payment penalty of .5% per month after 4/18/2022 until paid.
https://www.irs.gov/payments/penalties
