I already did the android 12 file if you want, but I want to do it yourself you can install termux on your phone, and then there are some steps :
To modify the font
1- install termux from Google play
Terminal emulator and Linux environment.
play.google.com
And make sure that the font you're going to edit inside downloads folder
2- open termux and type
termux-setup-storage
pkg install python
pip install fonttools
cd /storage
cd emulated
cd 0
cd Download
pyftsubset nameofthefont.ttf --unicodes=U+2000-2121,U+2123-F0000
Note that the cd steps might be different, for your phone, you can check the path using a file explorer
Also you'll need to allow termux to access files by going to the settings of your phone and by giving it the permission