postgresql server, can connect with SSL


I installed and used a Postgresql server a while back and have been using it with Postgis.
I would like to use my letsencrypt certificates with the server so i followed this article:
https://medium.com/@pavelevstigneev/postgresql-ssl-with-letsencrypt-b53051eacc22

The problem is that I can’t get it work.
If I follow the articles instructions and try to psql a database:

psql: error: could not connect to server: could not connect to server: No such file or directory Is the server running locally and accepting connections on Unix domain socket "/var/run/postgresql/.s.PGSQL.5432"?

Same with outside connections.

I installed postgresql 12 on a ubuntu server.
I followed every step in the article.
I use the certbot/letsencrypt certificates for apache2 and vsftpd

Questions i struggle with:
Is there an extra I forgot about?
Do i need to open an extra port on the firewall to enable the connection (other than 5432)?
Should I configure an extra subdomain in DNS so cerbot can make designated certificates?