Ns8 doesn’t have openvpn (what ns7 used for roadwarrior vpn). NS8 has wireguard as one of the main components but no official vpn module.
@mrmarkuz made a wireguard app for ns8 based on wg-easy which could fit your needs. In many cases, NS8 allows to have multiple instances of one app (though haven’t tried with wg-easy app).
On the other hand, many firewall and gateway functions common in ns7 are splitted and unavailable on ns8 but made their way into nethsecurity (based on openwrt), -as Alessio shared- you can take a look at it if it’s of your interest, or use another firewall.
What is the purpose, if we may ask?