christinajoylope,
Not sure which question you have: (a) how to print the 2019 return, or (b) whether if you mail the return it will be accepted.
I can answer (b): you still have another year to claim a 2019 refund by mailing in your return. Be sure to sign and date the signature area on page 2 of form 1040. You will need to attach copy B of any 2019 W-2's to the front of the return. Follow the mailing instructions on page 64 of the current form 1040 instructions https://www.irs.gov/pub/irs-pdf/i1040gi.pdf and use the appropriate mailing address from the back page 114.
