Custom font facebook

why my custom font (old south arabic-sabaean)didn’t work with facebook?
its work normally with whall multimedia except facebook.
https://keyman.com/keyboards/himyarit_musnad…

I’m not sure where the issue is.
However, I know that we cannot upload custom fonts to Facebook, so possibly that is the issue. The other issue is that if you are typing on a mobile device, we can only use the custom fonts within the Keyman application, the custom fonts will not work outside of the Keyman application.

Yes iam typing on a mobile device with keyman , when i used himyarit_musnad keybord in facebook its did not recognize font but like appear squares?
so I tried to use amharic keyboard
to compare its work good i hpoe we can fix this issue