If the estate, itself, is selling the property, it should be reported on Form 1041.
See https://www.irs.gov/instructions/i1041#en_US_2021_publink1000285942
If possession and title of the property has already passed, then any gain can be reported the same as if a stock, mutual fund, bond, had been sold in the program.
Note that the holding period for the property is long-term and the basis is the fair market value on the date of death of the decedent. As a result of the latter, if the property were sold shortly after the death of the decedent, there is likely to be little to no gain.
