Expat filed on June 16,. Do i need to file extension

I am an expat. I mailed my taxes one day late on June 16th. I do not own any taxes. I took corvid 19 vaccine and got sick. I had to wait 3 weeks to leave the house. My quarantine ended on June 16th and I mailed the taxes by express mail on the same date.

do I need to file an extension.  

After you file

First it is too late to file any extensions  at this late date   and  if you have a refund on the return an extension is not even needed.  

After you file

An extension has to be filed on or before May 17, 2021. 

If you do not have any taxes owed there are no penalties for filing a tax return after the due date.