[help]How to add a new font to phAB?

Could you please tell me how to add a new font to phAB?
My step is as following:
1.login as root
2.copy the new font to /usr/photon/font_repository
3.mkfontdir -b
But those ops don’t work. new font can’t be found and mouse is missing too.
Can you please tell me the right way to add a new font to PhAB? Thanks a lot!