Android Question Custom Notification Ringtone In Firebase Notification

Dim rp As RuntimePermissions
        Dim folder As String = rp.GetSafeDirDefaultExternal("shared")
        Dim FileName As String = ringtone
        'copy the file to the shared folder
        File.Copy(File.DirAssets, FileName, folder, FileName)
        Dim n As NB6
        n.Initialize("Channel1", Application.LabelName, "HIGH")
        n.SmallIcon(LoadBitmapResize(File.DirAssets, "icon.png", 32dip, 32dip, True))
        'disable the default sound
        n.SetDefaults(False, True, True)
        'set custom sound
        n.CustomSound(CreateFileProviderUri(folder, FileName))
        Dim Notification As Notification = n.Build(Title, Body, "", Me)
        Notification.Notify(3)

 var notification = new
            {
                to = key,
                data = new
                {
                    title = _title,
                    body = _message,
                    sound = ringtone,
                    device = deviceSerial,
                    mode = mode1,
                },
                notification = new
                {
                    title = _title,
                    body = _message,
                    sound = ringtone,  
                    device = deviceSerial,
                    mode = mode1,
                },
                priority = 10
            };