Use wget to download the ForticlientVPN from the link.

wget https://filestore.fortinet.com/forticlient/downloads/forticlient_vpn_7.0.0.0018_amd64.deb

Running the following command as a user with sudo privileges to install Chrome .deb package.

sudo dpkg -i forticlient_vpn_7.0.0.0018_amd64.deb