I can't find where is "Generate" button and "Levels" on jigsaw block because there is only for "Algined" and "Rollable" button.

here you can do step:

1: do /give @p jigsaw

2: place jigsaw block

3: edit jigsaw block

And see there is no found "Generate" button

This is sucks I can't make generate my village on superflat.

Always Java Edition they do.