public async Task SaveNewMapAsync(Viewpoint initialViewpoint, string title, string description, string[] tags)
{
// Get the ArcGIS Online portal
ArcGISPortal agsOnline = await ArcGISPortal.CreateAsync(new Uri("https://www.arcgis.com/sharing/rest"));
// Set the map's initial viewpoint using the extent (viewpoint) passed in
_map.InitialViewpoint = initialViewpoint;
// Save the current state of the map as a portal item in the user's default folder
await _map.SaveAsAsync(agsOnline, null, title, description, tags, null);
}