I have a ravioli maker, the kind that is rectangular and has 12 squares with 1" holes meant to be used with a rolling pin to seal the ravioli. I've never used it and have never made ravioli. I see online that it's meant to be used with a plastic press to create the sunken part to put the filling in. I don't have this press. Should I just push down with my fingers to make the pocket? Or is there some other way that might ensure uniformity?
Just push down gently with your thumbs; you want an impression that's about 1cm deep. There is no way to ensure uniformity if you have lost the insert.
You can just buy a replacement ravioli maker, which will have the plastic plate. I suppose you could even fabricate a replacement for the missing plate, but anything you make is liable to be more expensive than simply buying one.