Problem with custom model

Hi I'm new when it comes to this kind of things, i want try to making my own model or attachment like armor but it doesn't show the thing i made or its in the feet.

https://preview.redd.it/fwzrs95tfplg1.png?width=544&format=png&auto=webp&s=e59c08982454ab27955ee2f010901be2f550730f