@gjgogol
If you took it out of service on your 2020 return, then the sale in 2021 was the sale of personal property. You can report it under "Sale of your home." The program will ask when you lived there, and since you did not live there recently, all your gain will be taxable. You will also get asked if you previously claimed depreciation, you will need to enter that number which you can get from previous tax returns.
