sorry, but holding the property for less than 1-year results in ordinary income, not short-term capital gain. you should see the gain in section II of form 4797. that is transferred to schedule 1 line 4
you can see form 4797 instructions. look at the table line 2 on page 1
IRC section 1231 doesn't apply because the property was held for less than 1 year.
Https://www.irs.gov/pub/irs-pdf/i4797.pdf
