Started California single member LLC in 2020. Registered as S-corp with IRS. Income 35K. Will be closing LLC in 2020. Do I have to file 1120/use "business" turbotax?

Have about 20 K expenses but not worried about  getting benefits of dividents with S-Corp vs  1040 schedule C as a single proprietor.  I had both ways from CPAs and  intuit: must do 1120 or could just do 1040  schedule C.