yes, the deadline to pay was 4/18/2022. we have no way of knowing if you actually owe the $500 or not. the IRS may not have fully processed your return. if your return is fully processed there should be a transcript that can be used to compare to your return line by line to see if there are differences that can account for you not owing. generally, the IRS sends out notices for changes to returns but that could take a while after the return is processed.
https://www.irs.gov/individuals/get-transcript
