Not sure about medicals for PGWP. I did not have to do medicals for my PGWP, maybe it has changed now. For Express Entry, you are always supposed to submit your medicals along with your application. This is called upfront medicals and you can get them done by IRCC designated panel physicians. However, IRCC has made exceptions for people who couldn't get medicals done to COVID-19. In fact, some of the clinics were closed after instructions from IRCC. As far as I know, clinics have slowly re-opened for medicals. If you are able to get them done, submit it along with your e-APR.