Instructions:

1) Type a Gardiner code (1 consonant + number) example: A1

or a code from the Manuel de codage for hieroglyphic texts, example: zzmt

2) Type a space (or Enter)

3) Select the Egyptian hieroglyph (click with the mouse)

Download & install the font Aegyptus

Note:

This keyboard presents more than 5000 hieroglyphs, including the official unicodes & those from the book Hieroglyphica.

Copy [Ctrl]+[C] & Paste [Ctrl]+[V] on an image with a freeware like Paint (by selecting the font Aegyptus)
then possibly modify the place of the hieroglyphs (by presenting them, in certain cases, one on the other)