@Kmjo82 You can file a 2020 tax return to claim the Recovery Rebate Credit if no one can claim you as a dependent.
You don’t need to worry about a minimum amount of income to file. I believe the minimum you’re referring to is a minimum amount of income that requires you to file.
Disability may or may not be considered taxable income to be included on your return. Please see the TurboTax article Is disability income taxable?.
The IRS has provided a Recovery Rebate Credit Worksheet on page 59 of its Instructions for Forms 1040 and 1040-SR to help you see if and how much you might qualify for. There are also helpful calculators online.
[Edited 1/28/2021 | 7:37 am pst]
