Just specify your Pulse Secure VPN url through environment variable VPN_URL
and execute openconnect as privileged container:
docker run -ti --rm --privileged=true --name openconnect \
-e "VPN_URL=https://YOUR-CORPORATE-PULSES-ECURE-VPN.URL/dana-na/auth/url_default/welcome.cgi" \
andrius/openconnect-docker
It will ask for username, password and 2FA (OTP) password, these should be entered by user interactively
After openconnect started, it's good idea to check its routing: docker exec -ti openconnect bash
and netstat -nr
within container.