Bangle Js 2: Convert custom font not from google

Hi,
is there a way to convert a custom font (e.g. ttf) not listed on google to be usable by Bangle JS(2) ?
I have a font (stored locally) which I want to use in a Bangle JS watch face. I tried to use the espruino font converter by using a differnt URL with modified filed pointing to my self-hosted font but did not get it working.
Would it be possible to enable a custom font upload at font convert ? Or is there an offline tool available doing this job ?
Thank You.

If you've got the font hosted on an http server you should be able to just type the URL into the font converter and as long as it's able to load it from that website, it should work. The trick is the font family needs to be known as well, so you can do:

http://...../font.otf?family=My+Font+Fam­ily

Which gives it a hint. Supposedly Chrome does support TTF as well, but I get some strange stylesheet error in the chrome dev console when I try it.

Being able to upload a TTF directly would be great, but I don't think I ever managed to figure that out. If someone else can, it's be great if they could contribute the improvement though ;)