AFAIK the plugin does not export, only open. I think there is a bug report about that. The progress report bottom of Gimp window show an export but no file is produced.
These 2 made with the heif linux encoder, lenna-100 is lossless lenna-50 is 50% quality setting
So an example of code might not be any use.
These 2 made with the heif linux encoder, lenna-100 is lossless lenna-50 is 50% quality setting
So an example of code might not be any use.