It is too late to get a refund for a 2013 return. So there's nothing you need to file at this time unless you owed on the 2013 return but I'm sure the IRS would have notified you of this situation a couple of years ago at least.

So that you will know from now on....you have three years to file a tax return and receive a tax refund.  After that, the refund is forfeited.  You cannot wait as long as you tried to wait and file for 2013.  

So if you have any other past year returns lurking that have not been filed---the only ones you can still receive refunds for are 2017, 2018 or 2019.  You have until April 15, 2021 for a 2017 refund--after that a 2017 refund is forfeited.  P\

Past year returns have to be printed, signed and mailed.  They cannot be e-filed.

if you are due a refund, you have 3 years to file the tax return, otherwise you forfeit the refund.

BUT!!!  if you owe money, there is no time limit to file. So if you didn't file from years ago and you owe,. then you owe!