Lacerte has this snifty feature:
Go to where you expect the info/amount to appear. Right click on that field, then click on "jump to input". That will *usually* take you to where you to input the info (or give you the various options when there are multiple places).

You can also type 1042-S in the search box (upper right corner) & several help articles pop up.... you do have to page down to find the first one.

Before answering your question, we'd need to know:

• whether your client is an NRA; and
• of which country is your client a tax resident?