It's probably not going to work.

IRS expects 1042-S withholding to be on a 1040-NR.

Is it substantial? If not, I'd tell client to forego it this year and get it changed to a 1099 for 2024.

Thank you for your help. 

it's $105 withholding not any big amount. maybe I will enter it to Line 25B.

 But people will encounter this situation in which they file form 1040 (not form 1040NR) at the same time, they receive a form 1042-S from their job or other sources. If you search this question online, there is a solution for Turbotax to resolve or how to enter it.  But not proconnect online.

Hope someone knows a better way to handle this in Proconnect.

How about Schedule K-1 > Schedule K-1 Overrides > Other credits (Click on button to expand) 

You would need to do this allocation for each shareholder

Thanks, George, but your picture is from form 1120S.   my question was for form 1040/Line25C.   I will see there is a similar place on form 1040

Not sure why Turbotax and Pro series have the option to enter 1040/Line 25C but Not proconnect which is sucks and frustrating!!!!