How to enable the po file in the web-frontend

[Arcaneing]

As in the title,

I tried to put lang.po in skydata/skycultures/western/po, and changed the default language in index.vue and i rebuild web-frontend

But po does not seem to be in effect.

How should I enable po to translate star names.

About another question
The default font in the graphics engine does not seem to support utf-8 well, which part of the font should I change and recompile

Thanks to all the developers who responded to issues。