PRPC Activities only execute on the PRPC Application Server not in the Browser. You can trigger the execution of a PRPC Activity through a browser side Event as an Action using the PRPC Client Event Editor. You can learn more about how to use the PRPC Client event editor from this Help Topic: (https://pdn.pega.com/sites/pdn.pega.com/files/help_v71/procomhelpmain.h…).
i think you would have sorted this issue already.If not,solution - Create a HTML form at run time by document.createElement('FORM'); and attach all the parameters to it as elements and form.submit() using POST method in java script.
call this NonAutogenerated Section on Refresh through hidden section at invocation point.