My apologies for confusing you.  Somehow, I was thinking about PTO when the question is about PS.

PS does not link Sch C to F.2555 automatically, AFAIK.  You will first need to prepare the Sch C as you normally do.  You will then generate a F.2555 and manually plug in the foreign source gross income on Line 20a(2) of the 2555 Inc Wks-T or S with the relevant coding for sourcing followed by entering the deductions allocable from Sch C on Line 44.