Freepbx fax

Hi, I installed FreePBX 13.0.54, and now I’m trying to install free fax (full fax may be later…)
I tried to download Freefax from Sangoma site, then the license number… but I cannot figure aout ho to install in Freepbx and obtain a fax extension…
Is there some step-by-step howto I can follow?
How can I resolve.
Thanks for You attenzion.