Should be an easy fix. You need snow guards. I’m surprised whoever put the roof on didn’t install them. You should probably have them anywhere that people walk below the roof line as a safety measure. They will hold back the snow and then as it melts it will run into the gutter you need to install. There are lots of different kinds but I would avoid plastic ones or ones that secure only by an adhesive. Depending on the slope, panel profile, and usual snow load you may need a couple of layers of them rather than just one row.