If you click on "Save" the name of HEXSudoku and digits (eventually notes) which you have added will be saved to your computer by cookies. If you have forbidden cookies, the sudoku will not be saved.
When you check "as 2nd" 2nd cookie will be saved. You can load the first if you click on "Load", the second if you check "2nd" and click on "Load".
Tool Pen uses javascript. If Pen doesn´t work, permit javascript. Click on "Move" for transposition and after it on a place in plane.
If you click e.g. on "Show notes" and lose solved numbers, come back, save the sudoku and then continue.