https://docs.fortinet.com/document/forticlient/7.2.1/linux-release-notes/213138
I looked through the documentation on Fortigates website and it does look like it's different steps for installation based on which Ubuntu version you have. Also something different for Debian. Not sure which Linux mint you have or even if it's LMDE but I'd run through this doc page and see if anything works out for you.
Also obligatory nobody asked but zyxel has had a lot of severe security issues lately. Actually so has Fortinet so stay vigilant.
I liked it a lot. A little long but never really boring.
I agree with others that it was heavy handed in some parts but pulled it's punches in others.
But practical sets, a good script, great casting, and an original story. Hell yes. The 4 sequels are going to be trash and the eventual cinematic universe will be a lead-painted tire fire. But it was great.
Weirdly the "vibe" of the movie was similar to a Cohen Brothers movie. It reminded be of the Big Lebowski structure and pacing-wise.