Why do you want to create a separate openvpn server for each user? You can just add more clients to the same server.

What's stopping you from spinning up a new droplet and working through the guide, once again?

BTW, Is there any way to get notifications for any activity(ies) of my questions?

@Kamal I didn't say I'll create separate openvpn server for each user!!!
I said I want to create many servers for many clients that means each server has many clients.

@Pablo
I want to create many many servers on same droplet (under Windows I can do it easily by creating many ca(s) each pair of ca(s) in separate folder but under Ubuntu this didn't work)

I need to use multi OpenVPN servers because I want to separate the users to groups each group can't see the other groups because recently I noticed that some users use port listeners to discover the working ports for that I want to use different master keys and certificates (I was separate users groups on same server by using different IP ranges and ports but because all of the users have same ca.crt and ca.key they can easily discover the other groups).

You can have all clients under one server and stop them from communicating to other clients on the same OpenVPN networking, allowing them to access only the outer internet. Is that what you want?

BTW, Is there any way to get notifications for any activity(ies) of my questions?

Unfortunately we do not support that yet :(

@Kamal

No, I explained clearly what I want. I want to use separated groups may you please re-read what I posted above :\

If you stop them from communicating with other OpenVPN clients then they're totally seperate