I am truly ashamed to admit this, but I got stuck on puzzlemix.com Jigsaw Soduko 711. I made it half way through, but at the point shown, see
http://pairofdocs.net/wp-content/uploads/2023/03/NowWhat2.jpg, I have no idea what to do next. Some of the things I learned playing Enjoy Sudoku do not apply since this is a jigsaw board. If you can suggest what to try next, please let me know. Thanks.