Question Check if android or iOS or PC in WebGL

I have a code to check if the device is a mobile or not in my WebGL application. I want to improve this code to detect if the mobile is iOS or Android. How can I do this?

Plugin.jslib

Code (CSharp):

1.  var MyPlugin = {
2.      IsMobile: function()
3.      {
4.          return UnityLoader.SystemInfo.mobile;
5.      }
6. };
7. mergeInto(LibraryManager.library, MyPlugin);

Unity:

Code (CSharp):

1.      [DllImport("__Internal")]
2.      private static extern bool IsMobile();
3.      public bool isMobile()
4.      {
5.          #if !UNITY_EDITOR && UNITY_WEBGL
6.              return IsMobile();
7.          #endif
8.          return false;
9.      }