this layer has been made by Mustafa Bilgin developed on Ukulele keyboard editor
How to install? copy the ".keylayout" and with ".icns" file to Macintosh HD/Library/Keyboard Layout directory and restart your macOS and select in Setting/Keyboard/ input sources /others, and select old turkic keyboard.
default layer= consonant/vowel(1) shift layer= consonant(2) shift+option= syllables
note: the the khaganate flag ".icns" file created by Emir SARI [email protected], 2020.
for more his works; https://bitigchi.github.io/oldTurkic.html