Where has the 'Add to Collections' option gone in Mark up Capture?

The option for adding a web capture to a Collection seems to have disappeared. Has this permanently disappeared? We found this pretty useful for capturing an image or an image of text in inaccessible documents (e.g. PDF, online ebooks), but now it seems to have gone and there isn't any other alternative. For example pasting a capture into a Collection doesn't work (only accepts text).