USA Question Regarding GoSystem & Rental Election

[m33333m0ry]

Hello everyone,

I am practicing 1040NR with GoSystem, and my example has a rental property that he purchased for the first year.

Assuming that W-8eci has been already submitted, how should I elect the option of withholding on the net rental income instead of the gross income? I know that there is an option to tick, but can't really find it in GoSystem.

Thanks!