When you say “it didn’t work”, what exactly happens? If you’ve set Glyph Color to White and set up your grid sizes correctly, that should probably work fine
I checked with 3 browsers and it lets me pick PNG images on all of them, but even if not, you can usually switch the dropdown to “all files” and pick whatever you think is right.
Sorry, I forgot about this after figuring it out. It wouldn't let me select a png when clicking choose file but I was able to drag and drop it in. It worked great from there