Reading these things:
This image is deprecated. We will not offer support for this image and it will not be updated. We recommend our wireguard image instead for vpn: https://github.com/linuxserver/docker-wireguard
Maybe there are some plugins like openvpn that could be removed. In this case, installing wireguard through docker is simple and works better than openvpn.
Edit: I just posted a guide to installing Wireguard. I leave here the link for the one that may interest you. [How-To] Install Wireguard (VPN) in docker, server mode