Yes, you can file an amended return with Turbotax even though you did not use it originally. However, to do this you must,
1. buy a copy of Turbotax for 2021
2. prepare a return exactly as originally filed, and "file" it by saying you will file by mail and printing a copy (this will mark it in the system as "filed")
3. Save, quit the program, reopen it and prepare the amended return.
Your pro should prepare the amended return for free, if they made the error in the first place.
