To install the latest stable release of easy-openvpn from the Ubuntu store:
$ snap install easy-openvpn
All necessary plugs and slots will be automatically connected upon installation, except the home plug. You can verify this with:
$ snap interfaces
Slot Plug
[...]
:network easy-openvpn
:network-bind easy-openvpn
[...]
:firewall-control easy-openvpn
:network-control easy-openvpn
You probably need to connect the home plug manually if you copy the client ovpn file to your home directory and connect the client to server with it.
$ snap connect easy-openvpn:home :home