Help
I just see boxes.
This means that you don't have a font on your system that supports hieroglyph Unicode characters.
To find a font, check out this site and install it on your system.
Why can't I stack the hieroglyphs?
As of Unicode v.11, there are no control characters for the hieroglyph block.
In v.12 there will be supports and this app will be updated.
Of course, you will need a font that supports these control characters.