How do I install custom fonts like xfonts on WSL/WSLg for use in GUI apps?

I try to use GUI Apps on Windows 11 via WSL and WSLg. Unfortunately my GUI app needs some custom fonts (specifically xfonts-100dpi and xfonts-75dpi). Since WSLg does not include those fonts, my GUI App crashes. How can I install those fonts and make them available for WSLg (the x11 server)? I've installed them for WSL itself, but it does not look like they get shared with WSLg. Even manually copying the font files from /usr/share/fonts to /mnt/wslg/fonts did not change anything.