How to download file from s3 in pega constellation

I have used d_pxgetfile api to download file from s3, used in post processing activity in local action. iam able to download if run the activity standalone but not triggering download action when i submit in local action. Same activity worked in earlier pega version but not working in constellation

We can’t download the file in Constellation from Post processing though we can download with Standalone activity. We can get the base64 format through D_pxGetFile, however we can’t download.

This requires custom DX component.