There was a previous post regarding this...good luck finding it..   I believe the suggestion was to use Sched C F8829 worksheet to get your calculation then do Other Expense line entry with the amount

Does the client also qualify as a real estate professional?  Are they claiming the Section 199A deduction?  Does the Schedule E show a loss even before this deduction?  Whether a rental real estate enterprise is a trade or business is the subject of uncertainty for some taxpayers.  And some tax preparers.   I would proceed with caution.