xamarin.forms application not running on ios simulator - ios

Question

I am working on Xamarin.Forms app and it's working perfectly fine on Android device. Anyway, when I am trying to run it on iPhone simulator it's just showing the main screen of the app, but none of the features are working.
The main screen consists of two parts of which one is to browse and open files and the other is to open a menu. The layout consists of Browse, process and exit buttons and when I click on the browse button to open file explorer an alert is displayed, that something went wrong.
I enabled breakpoints and tried debugging it, but the control is going to catch exception part directly.
Here is the code for it can anyone please help me with this part? I am using Xamarin.Plugin.Filepicker NuGet package. When I place the cursor on the Exception I can see that
System.NotImplemented Exception:This functionality is not implemented in the portable version of this assembly,you should reference the NuGet Package from your main application project in order to reference the platform specific
and the code is
private Plugin.FilePicker.Abstractions.FileData file =
default(Plugin.FilePicker.Abstractions.FileData);
public async void OnBrowse(object o, EventArgs args)
{
try
{
// var file_path =
this.file = await CrossFilePicker.Current.PickFile();
if (this.file == null)
{
return;
}
string extensionType = this.file.FileName.Substring(
this.file.FileName.LastIndexOf(".",
StringComparison.Ordinal) + 1,
this.file.FileName.Length -
this.file.FileName.LastIndexOf(".", StringComparison.Ordinal) -
1).ToLower();
fileName = this.file.FileName;
if (extensionType.Equals("csv"))
{
csv_file.Text = (fileName);
}
else
{
await this.DisplayAlert("Name of the file:" + file.FileName, "File info", "OK");
}
if (SettingsPage.loggingEnabled)
{
LogUtilPage.Initialize("/storage/emulated/0");
}
}
catch (Exception e)
{
await DisplayAlert("Alert", "Something went wrong", "OK");
if (SettingsPage.loggingEnabled)
{
LogUtilPage.Log(e.Message);
}
}
}