At attachment plugin page I can see that it's enabled by default in Ikiwiki. Is it true?

No, typo (done). I don't want to enable it by default because it requires site-specific configuration to be made secure. --Joey

Thanks for your reply! I was guessing it --Paweł

I have backported Ikiwiki 2.52 and I need to add that plugin to add_plugins variable in my ikiwiki.setup file (and rebuild my wiki, of course) to see new upload buttons when I edit a page and click "Attachments" link.

FWIW, you don't need to rebuild the whole wiki, --refresh --wrappers is enough.

It's good to know. Thank you for the hint!

Maybe should I enable attachment handling in different way? --Paweł