Make an election under Code Section 871(d) to treat the rental income from all real property as income connected with United Stated Business.  With the election, the reporting for the rental activities goes to Sch E and Sch 1 Line 5 then 1040NR Line 8.

In Lacerte, the election is NOT one of those pre-set elections and has to be set up under "Other Election on the bottom of  Screen 46

Without making the election, the gross rent will be reported on Sch NEC and taxed according to the rate applicable to the taxpayer. 

Hope this helps.