You will not be entering itemized deductions. You can file a 2020 return and enter your disability income and use the recovery rebate credit to get the first two stimulus checks if you did not receive them.
Do you have a SSA1099 for the disability?
Go to Federal> Wages & Income>>Retirement Plans and Social Security (SSA1099 and 1099RRB) to enter your SSA1099.
The stimulus check is an advance on a credit you can receive on your 2020 tax return. If something went wrong or you did not get the stimulus check in 2020, you can get it when you file your 2020 return in early 2021
The Recovery Rebate Credit will be found in the FEDERAL REVIEW section. ( you should see "Let's make sure you got the right stimulus amount”) If you are eligible it will end up on line 30 of your 2020 Form 1040.
Make sure that you enter ALL of the stimulus money received for the 1st and 2nd stimulus for yourself, your spouse and your children.
Click on Tax Tools on the left side of the screen. Click on Tools. Click on View Tax Summary. Click on Preview my 1040 on the left side of the screen.
You can't efile your return if you only have SS or SSDI. You can print and mail it. If you want to efile which is faster you can enter $1 of interest to let you efile. Make up a fake 1099Int.
Enter a 1099-Int under
Wages & Income
Interest and Dividends
Interest on 1099INT - Click the Start or Update button
Put the interest amount in box 1