Sure ... pick one of the 10  totally  FREE options from the IRS site and follow the screen instructions :  

https://www.irs.gov/filing/free-file-do-your-federal-taxes-for-free

The 1040 SR is just a regular tax return but larger type for people over 65.  If you didn't file a tax return you need to file one to get any of the missing 1st or 2nd Stimulus payments.