On January 10th, 2024, the IRS communicated that will remove/waive failure to pay penalties on unpaid taxes less than $100k for tax years 2020 or 2021.
The rational for this removal of penalties is because the IRS suspended sending automated notices during the pandemic so certain taxpayers were not aware of any amounts due for 2020 or 2021. However, keep in mind that even if the failure to pay penalties are removed, there might be still other penalties applied and there are interest calculated from the original amount due.
Note that this is a retroactive measure, so if you qualify for this waiver and you paid those penalties, you should expect a refund check from the IRS. If you think you qualify for this waiver and you do not receive a refund, then, reach out to the IRS to investigate the status and confirm your claim.