Unclear usage of font awesome icons in jquery context menu

Question

I am trying to use the free font-awesome in the jquery ContextMenu plugin (https://swisnl.github.io/jQuery-contextMenu/docs/font-awesome.html). However, it is not clear to me why it is working for some icons and not for others (from the free icons set):

Example in the fiddle: https://jsfiddle.net/4ey3nx9t/

I changed the icon for item entry "edit" from the sample code below to fa-solid fa-magnifying-glass as suggested by fontawesome. However, this one doesn't work.

I changed the icon for item entry "cut" to fa-solid fa-stethoscope and it worked fine.

Please note that I added fas to the icon, as otherwise the font would be bold. I don't know why that is.

Any clue as to why this is? How can I use all the free font-awesome icons?

        items: {
            "edit": {name: "Edit", icon: "fas fa-solid fa-magnifying-glass"},
            "cut": {name: "Cut", icon: "fas fa-solid fa-stethoscope"},
           copy: {name: "Copy", icon: "copy"},
            "paste": {name: "Paste", icon: "paste"},
            "delete": {name: "Delete", icon: "delete"},
            "sep1": "---------",
            "quit": {name: "Quit", icon: function(){
                return "context-menu-icon context-menu-icon-quit";
            

Answer 1

<script type="text/javascript">
    jQuery(function ($) {
        $("#contextMenu").ejMenu({
      menuType: ej.MenuType.ContextMenu,
      openOnClick: false,
      contextMenuTarget: "#target"
  });
    });
</script>

Font Awesome is a font and icon toolkit based on CSS and LESS. You can use the font awesome icons in to your sample by referring the font awesome library in header section.