Local Blynk Server Security

Hello everyone.

I’ve come to ask friends from here, help to give good security to my local Blynk server. It turns out that some time ago I installed version 0.18 on my server. Because of the work I was some time without using my server.
Now, after upgrading the server to version 0.22 I saw that some things have changed and I can’t follow, for example, after creating a new project I don’t receive my token by email, but the part that most worries me is the security of the server accessed by an external network.
Because, a friend from here does by kilometers distance a new account on my server acesscing by a outside network. Because of this I know that I need improve my server security, I know that doesn’t have anything related about the Blynk Server but yes with my configurations but I don’t have ideia of how do this and because of this I’ve come to ask help of everyone to do this.
All and any help will be welcome.

By now, thanks to everyone.