If you could explain it would be much appreciated!
When creating your button, the third argument is the id of the decal that will be used as an icon for your plugin. For example, this script will use this decal for the plugin icon :
Toolbar = plugin:CreateToolbar("SofloannsToolbar") ToolbarButton = Toolbar:CreateButton("", "PluginName", "http://www.roblox.com/asset/?id=153138171")