Rejection for duplicate information

Hello, I got refund for 2019 this year and I want to fill out one more form for 2020,but I got this letter. How should I solve this problem.

We could not e-file your return for the following reason:

Duplicate Social Security Number: A tax return with the same Social Security number has already been submitted - in other words, it appears you're trying to e-file the same return twice. If you need to change this return, you'll need to file an amended return on paper, by mail. Duplicate Social Security Number: A tax return with the same Social Security number has already been submitted - in other words, it appears you're trying to e-file the same return twice. If you need to change this return, you'll need to file an amended return on paper, by mail.