XnView Software

I do have it. Unfortunately for some reason saving doesn't work system wide, in Paint neither.

EDIT: ok I found out that it is also needed to install HEVC, which isn't free. Maybe it would be worthwhile to implement HEIC saving in XnView natively?

So how can I save heic files with xnview? What is store component and how do I install it?

Here XnViewMP creates HEIC files of 0 size. Saving dialog disappears quickly but I can't delete the bogus files until I quit XnViewMP.

EDIT: same with XnConvert, I get a not a picture error though.