Yes Steve Model Mod (1.21.1) | Customize Your Model

Hi, I'm playing on a server with a friend, when I go to the page to download the files only some come in .zip format and those work (but there are very few that come in this format), the others come in .ysm format which don't work when I put them in the custom folder since only that .ysm file is downloaded and no more, I don't know what to do since I want to use a skin but it's in .ysm and it doesn't work