How to add new font to simulator?

I’m trying to edit the font in the default A320neo to be more accurate (using Liberation Mono instead of Roboto), but even with putting the font in the right directory, referencing it correctly in the CSS file, adding the TTF to layout.json, and using it, it defaults back to Roboto and refuses to use the new font.

Can anyone help? Thanks

Don’t web fonts need to be WOFF and not TTF?

I haven’t looked at it yet, but I can’t recall ever being able to load straight TTF fonts from the stylesheet.