Passive losses carried over to 2020 and not allowed on your 2020 return for whatever reason will be shown on IRS Form 8582.
PART I is for rental real estate activity and the loss to be carried over to 2020 is on line "d".
If you have more than one rental property then you need to know the carry over loss for each property individually. You'll find that on page 2 of the 8582 in Worksheet 1, column (e). The amount in column (c) is the carry over from last years 2018 return, to this year's 2019 return.
