I have a problem trying to generate the document with: xelatex src/front.tex

It is generated but without icons. If I see the file front.log I think it's trying to write the icons using Fira Sans:

  Missing character: There is no  in font Fira Sans/OT:script=latn;language=DFLT;mapping=tex-text;!

(The line shows 9 times and there are 9 icons too)

I tried everything but I have never used before Latex, so it's really complicated. Any comment will be very welcome.

Thanks.