protected override async void OnClick()
{
  var activeMap = MapView.Active?.Map;
  if (activeMap == null) return;
  var location = @"C:/Data/FeatureTest/FeatureTest.gdb";
  var name = @"TestLinesAnno";

  await QueuedTask.Run(() =>
  {
    List<Layer> layersToRemove = new List<Layer>();
    
 
foreach (AnnotationLayer annotationLayer in activeMap.GetLayersAsFlattenedList().OfType<AnnotationLayer>())
    {
      using (AnnotationFeatureClass featureClass = annotationLayer.GetFeatureClass() as AnnotationFeatureClass)
      {
        if (featureClass != null)
        {
          using (var
 
 dataStore = featureClass.GetDatastore())
          {
            if (dataStore.GetPath().AbsolutePath == location &&
                featureClass.GetName() == name)
            {
              layersToRemove.Add(annotationLayer);
            }
          }
        }
      }
    }
    activeMap.RemoveLayers(layersToRemove);

  });
}‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍