I thought I found a Cisco Anyconnect VPN client for Linux a couple of weeks ago and there is a link to a page to get one in the official download/install documents but it just takes you to the windows/mac download page which is kind of annoying. I wonder if they just didn't have enough usage to make it worthwhile to maintain.
How to Setup a VPN Client on Linux | Full Configuration Feb 07, 2020 Installing and Using the Linux OpenConnect client with UCI Dec 13, 2018 Anyconnect Installation & Configuration Guide
The Gatorlink VPN service is based primarily on th Cisco Anyconnect VPN client. This client supports a wide range of operating systems including Windows ,Mac, Linux, Apple IOS and Android. It is based on SSL transport rather than IPsec which was supported by the older client.
Connect to Cisco VPN Using PCF file on Ubuntu Install Cisco-compatible VPN client. To use PCF file while connecting to Cisco VPN Ubuntu and other Debian derivatives, you need to install Cisco-compatible VPN client (vpnc) and GNOME GUI plugin for VPNC. This can be done by simply executing the command below; apt install vpnc network-manager-vpnc How to Connect to Cisco AnyConnect VPN in Ubuntu
This article covers steps for installing Cisco AnyConnect on a Windows machine with a University of Minnesota profile built in. If you are looking for instructions for how to install AnyConnect on a Mac, see Install AnyConnect VPN for Mac OS X. For instructions on how to connect to the University's VPN with AnyConnect, see connection instructions.
Cisco AnyConnect VPN - Installing the VPN Client and Jul 13, 2012 How do I install and use UIC VPN on Linux?