I'm trying to insert an image into the header of an Excel worksheet programmatically from an Office JS taskpane.

I can load the image into the worksheet just fine, I can move it all over the sheet's range. I can also access the header and edit the text inside. But I can't find a way to get an image into the header.

I know from this tutorial that it's possible in VBA by updating sheet.PageSetup.LeftFooterPicture.Filename, and I know from this answer that it's possible in Office JS for Word by accessing footer.Shapes, so I'm optimistic that it's possible, but I can't find any info on it.